The DOI matches its Crossref record; 107 of the 107 references it cites were found in a registry or an index; 11 of the 113 sources its claims cite were checked for support.
Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis
Open accessAbstract
Skeletal muscle is a highly plastic tissue that plays a central role in human health and disease. Aging is associated with a decrease in muscle mass and function (sarcopenia) that is associated with a loss of independence and reduced quality of life. Gut microbiota, the bacteria, archaea, viruses, and eukaryotic microbes residing in the gastrointestinal tract are emerging as a potential contributor to age-associated muscle decline. Specifically, advancing age is characterized by a dysbiosis of gut microbiota that is associated with increased intestinal permeability, facilitating the passage of endotoxin and other microbial products (e.g., indoxyl sulfate) into the circulation. Upon entering the circulation, LPS and other microbial factors promote inflammatory signaling and skeletal muscle changes that are hallmarks of the aging muscle phenotype. This review will summarize existing literature suggesting cross-talk between gut microbiota and skeletal muscle health, with emphasis on the significance of this axis for mediating changes in aging skeletal muscle size, composition, and function.
Overview
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Written from the paper’s full text.
TL;DR
This review proposes a gut-muscle axis in which age-related gut dysbiosis increases intestinal permeability and circulating LPS/microbial metabolites, promoting inflammation and skeletal muscle atrophy, fat infiltration, and functional decline. It synthesizes murine and human evidence suggesting probiotics, prebiotics, and exercise may help mitigate sarcopenia.
Key findings
- Aging is associated with a less diverse gut microbiota, reduced butyrate-producing bacteria and *Bifidobacterium*/*Lactobacillus*, and increased Proteobacteria/Enterobacteriaceae; these changes accompany increased intestinal permeability and elevated circulating LPS. In older humans, circulating LPS and skeletal muscle TLR4 expression/content were higher than in younger counterparts.
- LPS and microbial metabolites promote muscle catabolism: high-fat-fed mice showed 2- to 3-fold elevated circulating LPS; LPS infusion induced pro-inflammatory cytokines and impaired glucose tolerance in wild-type but not CD-14 mutant mice. Indoxyl sulfate increased IL-6/TNF-α and atrophy markers (myostatin, atrogin-1) in cultured myocytes and increased atrogene expression with decreased muscle mass in mice.
- Microbiota-targeted interventions affect muscle outcomes: *Lactobacillus reuteri* and *L. gasseri* decreased IL-6/MCP-1 and MuRF1/Atrogin-1 and increased tibialis anterior mass in leukemic mice; prebiotic oligofructose decreased circulating LPS/inflammation and increased muscle mass in obese mice; prebiotic inulin plus fructooligosaccharides increased handgrip strength and endurance in frail older adults.
- Human observational links include frail advanced agers (n = 23; ~86 years) showing ~8-fold less *Lactobacillus* and ~6-fold more Enterobacteriaceae, and a larger older cohort (n = 178; ~78 years) in which community dwellers had more butyrate-producing microbes than long-stay residents; athletes had greater microbial diversity than healthy and overweight controls.
Methods
- Design: narrative review of existing literature; no systematic review, meta-analysis, or primary data collection methods are stated.
- Data/sample: synthesizes animal and human studies, including germ-free and conventional mice, high-fat diet models, leukemic/cachectic mice, obese mice, and human cohorts of older adults, frail elders, and athletes.
- Main analysis: qualitative integration of findings to propose an endocrine gut-muscle communication axis linking age-related dysbiosis, intestinal permeability, circulating LPS/metabolites, inflammation, and skeletal muscle size, composition, and function.
Limitations
- Stated: the authors note an inability to distinguish whether changes in microbiota are a driver or a product of compromised bone and muscle integrity; probiotic rescue in mice is cited as suggesting initiation, but causality remains unresolved.
- Evident: as a narrative review, it lacks systematic search and quality appraisal and does not quantify pooled effects; much mechanistic evidence is from murine models, and human evidence is largely cross-sectional or associational, limiting causal inference.
- Evident: several cited human studies are small (e.g., n = 23 frail agers) or observational, and the review states it could not identify any studies showing *Bifidobacterium* supplementation increases muscle mass.
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Claims the paper makes
62 Not checked yet · 17 Own interpretation · 2 Supported · 2 Partly supported · 1 No basis given · accuracy not yet measured
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“probiotic rescue (Lactobacillus reuteri and gasseri) of inflammation and muscle/bone loss in mice proposes that gut microbiota initiate this relationship [19, 67, 89].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Composition
What the sources say
- Partly supportedcites [19] Bindels LB, Beck R, Schakman O, Martin JC, de Backer F, Sohet FM, Dewulf EM, Pachikian BD, Neyrinck AM, Thissen JP, Verrax J, Calderon PB, Pot B, Grangette C, Cani PD, Scott KP, Delzenne NM (2012) Restoring specific lactobacilli levels decreases inflammation and muscle atrophy markers in an acute leukemia mouse model. PLoS ONE 7:1–10 sourceExperimental — accuracy not yet measured
The Results report that L. reuteri and L. gasseri supplementation reduced inflammatory cytokines and muscle atrophy markers in leukemic mice; the Discussion proposes a role for gut microbiota in these changes. The cited passages do not report bone loss or its rescue, and they do not establish that gut microbiota initiate the relationship. (LLM, conf=0.88)
- Partly supportedcites [67] Bindels LB, Neyrinck AM, Claus SP, Le Roy CI, Grangette C, Pot B, Martinez I, Walter J, Cani PD, Delzenne NM (2016) Synbiotic approach restores intestinal homeostasis and prolongs survival in leukaemic mice with cachexia. ISME J 10:1456–1470 sourceExperimental — accuracy not yet measured
The Results section (‘A synbiotic approach reduces the progression of cancer and associated cachexia’; page unavailable) reports that a previous study found a mixture of L. gasseri and L. reuteri reduced systemic inflammation and muscle atrophy in leukaemic mice. This paper’s own intervention used L. reuteri with a prebiotic, not both bacteria. The cited passage does not report rescue of bone loss, and the Discussion asks whether microbiota changes contribute to the pathology rather than establishing that they initiate it. (LLM, conf=0.88)
- Partly supportedcites [89] Britton RA, Irwin R, Quach D, Schaefer L, Zhang J, Lee T, Parameswaran N, McCabe LR (2014) Probiotic L. reuteri treatment prevents bone loss in a menopausal ovariectomized mouse model. J Cell Physiol 229:1822–1830 sourceExperimental — accuracy not yet measured
The Results and Discussion (page numbers unavailable) report that L. reuteri protected ovariectomized mice from bone loss, reduced a bone-marrow immune-cell increase, and altered gut microbial communities. The paper does not study L. gasseri or muscle loss. Its Discussion treats a direct role for the microbiota in bone loss as a possibility still under investigation, not an established initiating mechanism. (LLM, conf=0.88)
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: Findings from animal models (mice, rats, pigs) about gut microbiota and skeletal muscle can be generalized to humans.
- Partly supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“regular physical activity may help to combat reductions in butyrate-producing microbiota (Clostridiales, Roseburia, Lachnospiraceae, and Erysipelotrichaceae) [102] and Lactobacillus levels [103] that are commonly seen with aging [15, 84, 98].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Function
What the sources say
- Supportedcites [102] Estaki M, Pither J, Baumeister P, Little JP, Gill SK, Ghosh S, Ahmadi-Vand Z, Marsden KR, Gibson DL (2016) Cardiorespiratory fitness as a predictor of intestinal microbial diversity and distinct metagenomic functions. Microbiome 4:42 source
The Conclusions link fitness with a microbiome profile favoring butyrate production, potentially through increases in the four groups named in the claim, and describe the findings as consistent with a role for physical activity. The study is correlative, which fits the claim’s cautious “may.” In the citing sentence, this source is attached to the butyrate-producing groups; Lactobacillus and aging have separate citations. (LLM, conf=0.90)
- Not checked yetcites [103] Denou E, Marcinko K, Surette MG, Steinberg GR, Schertzer JD (2016) High-intensity exercise training increases the diversity and metabolic capacity of the mouse distal gut microbiota during diet-induced obesity. Am J Physiol Endocrinol Metab 310:E982–E993 source
- Partly supportedcites [15] Rampelli S, Candela M, Turroni S, Collino EB, Franceschi C, O’Toole PW, Brigidi P (2013) Functional metagenomic profiling of intestinal microbiome in extreme ageing. Aging 5:902–912 sourceExperimental — accuracy not yet measured
The Discussion (page unavailable) reports an age-related loss of genes involved in short-chain-fatty-acid production and a loss of several fibrolytic microorganisms in the extremely aged microbiome. It does not establish age-related declines in the listed Clostridiales, Roseburia, Lachnospiraceae, Erysipelotrichaceae, or Lactobacillus; it mentions Roseburia in connection with reduced carbohydrate intake instead. The physical-activity proposition is attached to other citations, not this one. (LLM, conf=0.82)
- Not checked yetcites [84] van Tongeren S, Slaets J, Harmsen H, Welling G (2005) Fecal microbiota composition and frailty. Appl Environ Microbiol 71:6438–6442 source
- Partly supportedcites [98] Claesson MJ, Jeffery IB, Conde S, Power SE, O’Connor EM, Cusack S, Harris HMB, Coakley M, Lakshminarayanan B, O’Sullivan O, Fitzgerald GF, Deane J, O’Connor M, Harnedy N, O’Connor K, O’Mahony D, van Sinderen D, Wallace M, Brennan L, Stanton C, Marchesi JR, Fitzgerald AP, Shanahan F, Hill C, Ross RP, O’Toole PW (2012) Gut microbiota composition correlates with diet and health in the elderly. Nature 9:178–184 sourceExperimental — accuracy not yet measured
The introduction (p. 5) says older adults’ microbiota differs from that of younger adults, and ‘Microbiota structure and healthy ageing’ (p. 10) reports fewer butyrate-producing genera along a microbiota gradient within the elderly cohort. The paper does not establish that the listed taxa or Lactobacillus commonly decline with age; its observed gradient is not a direct comparison across ages. The physical-activity proposition is attached to other citations, not this one. (LLM, conf=0.82)
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Supported
Every source the paper cites for this claim was checked and supports it.
In the paper
“two independent studies have observed changes in skeletal muscle MHC composition following interventions aimed at manipulating gut microbiota [63, 94].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Composition
What the sources say
- Supportedcites [63] Chen YM, Wei L, Chiu YS, Hsu YJ, Tsai TY, Wang MF, Huang CC (2016) Lactobacillus plantarum TWK10 supplementation improves exercise performance and increases muscle mass in mice. Nutrients 8:205 source
The Methods (§2.7) describe staining mouse gastrocnemius muscle for fast and slow myosin heavy chain (MHC). The Results (§3.6) report more type I fibers after Lactobacillus plantarum TWK10 supplementation than after vehicle treatment. This supports the cited paper as one of the studies observing a change in MHC-related muscle fiber composition; the other cited study is not assessed here. (LLM, conf=0.90)
- Supportedcites [94] Yan H, Diao H, Xiao Y, Li W, Yu B, He J, Yu J, Zheng P, Mao X, Luo Y, Zeng B, Wei H, Chen D (2016) Gut microbiota can transfer fiber characteristics and lipid metabolic profiles of skeletal muscle from pigs to germ-free mice. Sci Rep 6:31786 source
The Results section reports that germ-free mice given microbiota from different pig breeds differed in skeletal-muscle myosin heavy-chain isoform gene expression: MYH7 was higher and MYH4 lower in recipients of Rongchang pig microbiota. The Methods section identifies fecal microbiota transplantation as the intervention, so this paper supports the claim as one of the two cited studies. (LLM, conf=0.90)
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Supported
None of the sources cited for this claim have been checked yet.
In the paper
“In later years (> 65 years), however, the proclivity for aberrant changes in microbial composition appears to accelerate [13–15].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Introduction
What the sources say
- Not checked yetcites [13] Langille MG, Meehan CJ, Koenig JE, Dhanani AS, Rose RA, Howlett SE, Beiko RG (2014) Microbial shifts in the aging mouse gut. Microbiome 2:50 source
- Not checked yetcites [14] Thevaranjan N, Puchta A, Schulz C, Naidoo A, Szamosi JC, Verschoor CP, Loukov D, Schenck LP, Jury J, Foley KP, Schertzer JDL, Maggie J, Davidson DJ, Verd EF, Surette MG, Bowdish D (2017) Age-associated microbial dysbiosis promotes intestinal permeability, systemic inflammation, and macrophage dysfunction. Cell Host Microbe 21:455–466 source
- Not checked yetcites [15] Rampelli S, Candela M, Turroni S, Collino EB, Franceschi C, O’Toole PW, Brigidi P (2013) Functional metagenomic profiling of intestinal microbiome in extreme ageing. Aging 5:902–912 source
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“To conclude, we will integrate these findings and propose a “gut-muscle axis” that we believe plays a role in the age-related loss of muscle mass and function (sarcopenia) [24].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Introduction
What the sources say
- Not checked yetcites [24] Fielding RA, Vellas B, Evans WJ, Bhasin S, Morley JE, Newman AB, Abellan van Kan G, Andrieu S, Bauer J, Breuille D, Cederholm T, Chandler J, De Meynard C, Donini L, Harris T, Kannt A, Keime Guibert F, Onder G, Papanicolaou D, Rolland Y, Rooks D, Sieber C, Souhami E, Verlaan S, Zamboni M (2011) Sarcopenia: an undiagnosed condition in older adults. Current consensus definition: prevalence, etiology, and consequences. International working group on sarcopenia. J Am Med Dir Assoc 12:249–256 source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: Findings from animal models (mice, rats, pigs) about gut microbiota and skeletal muscle can be generalized to humans.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“These findings suggest that an age-related increase in LPS levels might contribute to the greater occurrence of diabetes in older persons.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
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None of the sources cited for this claim have been checked yet.
In the paper
“excess nutrient uptake and storage (i.e., obesity) is associated with low microbial diversity and changes in the relative abundance of the major bacterial phyla (Bacteroidetes and Firmicutes) [27–29].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
What the sources say
- Not checked yetcites [27] Vrieze A, Nood E, Holleman F, Salojärvi J, Kootte R, Bartelsman J, Dallinga G, Thie Ackermans M, Serlie M, Oozeer R, Derrien M, Druesne A, Van Hylckama Vlieg J, Bloks V, Groen A, Heilig H, Zoetendal E, Stroes E, De Vos W, Hoekstra J, Nieuwdorp M (2012) Transfer of intestinal microbiota from lean donors increases insulin sensitivity in individuals with metabolic syndrome. Gastroenterology 143:913–916 source
- Not checked yetcites [28] Turnbaugh PJ, Hamady M, Yatsunenko T, Cantarel BL, Duncan A, Ley RE, Sogin ML, Jones WJ, Roe BA, Affourtit JP, Egholm M, Henrissat B, Heath AC, Knight R, Gordon JI (2009) A core gut microbiome in obese and lean twins. Nature 457:480–484 source
- Not checked yetcites [29] Le Chatelier E, Nielsen T, Qin J, Prifti E, Hildebrand F, Falony G, Almeida M, Arumugam M, Batto J-M, Kennedy S, Leonard P, Li J, Burgdorf K, Grarup N, Jørgensen T, Brandslund I, Nielsen HB, Juncker AS, Bertalan M, Levenez F, Pons N, Rasmussen S, Sunagawa S, Tap J, Tims S, Zoetendal EG, Brunak S, Clément K, Doré J, Kleerebezem M, Kristiansen K, Renault P, Sicheritz-Ponten T, de Vos WM, Zucker J-D, Raes J, Hansen T, Bork P, Wang J, Ehrlich SD, Pedersen O, Guedon E, Delorme C, Layec S, Khaci G, van de Guchte M, Vandemeulebrouck G, Jamet A, Dervyn R, Sanchez N, Maguin E, Haimet F, Winogradski Y, source
plaincorrelational- Asserted: passes — The authors put it forward as true.
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- Based: passes — The paper gives a reason why it holds.
In the paper
“who demonstrated that fecal microbiota transplant from obese humans into lean animals precipitated body composition shifts consistent with the phenotype of their donor”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Introduction
What the sources say
- Not checked yetcites [6] Ridaura VK, Faith JJ, Rey FE, Cheng J, Alexis E, Kau AL, Griffin NW, Lombard V, Henrissat B, Bain JR, Muehlbauer MJ, Ilkayeva O, Semenkovich CF, Funai K, Hayashi DK, Lyle BJ, Martini MC, Luke K, Clemente JC, Treuren WV, Walters WA (2014) Cultured gut microbiota from twins discordant for obesity modulate adiposity and metabolic phenotypes in mice. Science 341:1–22
boosteddirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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In the paper
“facilitating the passage of endotoxin and other microbial products (e.g., indoxyl sulfate) into the circulation”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Abstract
What the sources say
- Not checked yetcites [14] Thevaranjan N, Puchta A, Schulz C, Naidoo A, Szamosi JC, Verschoor CP, Loukov D, Schenck LP, Jury J, Foley KP, Schertzer JDL, Maggie J, Davidson DJ, Verd EF, Surette MG, Bowdish D (2017) Age-associated microbial dysbiosis promotes intestinal permeability, systemic inflammation, and macrophage dysfunction. Cell Host Microbe 21:455–466 source
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“pro-inflammatory cytokine induction and impairments in glucose tolerance were observed exclusively in the wild-type animals.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
What the sources say
- Not checked yetcites [18] Cani PD, Amar J, Iglesias MA, Poggi M, Knauf C, Bastelica D, Neyrinck AM, Fava F, Tuohy KM, Chabo C, Ferrie J, Gibson GR, Casteilla L, Delzenne NM, Alessi MC (2007) Metabolic endotoxemia initiates obesity and insulin resistance. Diabetes 56:1761–1772 source
plain- Asserted: passes — The authors put it forward as true.
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In the paper
“bacterial colonization of GF mice appears to decrease skeletal muscle metabolic efficiency, as evidenced by an increase in tricarboxylic acid cycle intermediates without an appreciable increase in high-energy phosphate stores [31].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
What the sources say
- Not checked yetcites [31] Bäckhed F, Ding H, Wang T, Hooper LV, Koh GY, Nagy A, Semenkovich CF, Gordon JI (2004) The gut microbiota as an environmental factor that regulates fat storage. Proc Natl Acad Sci USA 101:15718–15723 source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“Compared to mice with gut microbiota, skeletal muscle from GF mice was characterized by markedly greater activity of AMP-activated protein kinase (AMPK) and carnitine palmitoyl transferase-1 (CPT-1), indicative of an elevated oxidative capacity.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
What the sources say
- Not checked yetcites [23] Bäckhed F, Manchester JK, Semenkovich CF, Gordon JI (2007) Mechanisms underlying the resistance to diet-induced obesity in germ-free mice. Proc Natl Acad Sci USA 104:979–984 source
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
None of the sources cited for this claim have been checked yet.
In the paper
“In later years (> 65 years), however, the proclivity for aberrant changes in microbial composition appears to accelerate [13–15].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Introduction
What the sources say
- Not checked yetcites [13] Langille MG, Meehan CJ, Koenig JE, Dhanani AS, Rose RA, Howlett SE, Beiko RG (2014) Microbial shifts in the aging mouse gut. Microbiome 2:50 source
- Not checked yetcites [14] Thevaranjan N, Puchta A, Schulz C, Naidoo A, Szamosi JC, Verschoor CP, Loukov D, Schenck LP, Jury J, Foley KP, Schertzer JDL, Maggie J, Davidson DJ, Verd EF, Surette MG, Bowdish D (2017) Age-associated microbial dysbiosis promotes intestinal permeability, systemic inflammation, and macrophage dysfunction. Cell Host Microbe 21:455–466 source
- Not checked yetcites [15] Rampelli S, Candela M, Turroni S, Collino EB, Franceschi C, O’Toole PW, Brigidi P (2013) Functional metagenomic profiling of intestinal microbiome in extreme ageing. Aging 5:902–912 source
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Upon entering the circulation, LPS and other microbial factors promote inflammatory signaling and skeletal muscle changes that are hallmarks of the aging muscle phenotype.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Abstract
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: unclear — It is unclear why the paper says it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Taken together, these early studies suggest that gut microbiota can influence body composition by means of regulating skeletal muscle bioenergetic pathways.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
None of the sources cited for this claim have been checked yet.
In the paper
“evidence also suggests that gut microbiota may impact distal metabolic activity in skeletal muscle tissues [23, 30].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
What the sources say
- Not checked yetcites [23] Bäckhed F, Manchester JK, Semenkovich CF, Gordon JI (2007) Mechanisms underlying the resistance to diet-induced obesity in germ-free mice. Proc Natl Acad Sci USA 104:979–984 source
- Not checked yetcites [30] Choi Y, Kwon Y, Kim D-K, Jeon J, Jang SC, Wang T, Ban M, Kim M-H, Jeon SG, Kim M-S, Choi CS, Jee Y-K, Gho YS, Ryu SH, Kim Y-K (2015) Gut microbe-derived extracellular vesicles induce insulin resistance, thereby impairing glucose metabolism in skeletal muscle. Sci Rep 5:15878 source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“Age-related inflammation is associated with reductions in skeletal muscle size and function (sarcopenia) [44].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [44] Jensen GL (2008) Inflammation: roles in aging and sarcopenia. J Parenter Enteral Nutr 32:656–659 source
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
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- Based: passes — The paper gives a reason why it holds.
In the paper
“their influence on metabolic function (e.g., nutrient absorption and amino acid synthesis) [25]”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
What the sources say
- Not checked yetcites [25] Jumpertz R, Le DS, Turnbaugh PJ, Trinidad C, Bogardus C, Gordon JI, Krakoff J (2011) Energy-balance studies reveal associations between gut microbes, caloric load, and nutrient absorption in humans. Am J Clin Nutr 94:58–65 source
plaindirect- Asserted: passes — The authors put it forward as true.
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- Based: passes — The paper gives a reason why it holds.
In the paper
“Backhed et al. infused germ-free (GF) mice, animals born and raised in sterile conditions and lacking a microbiome, with the cecal contents of conventionally raised animals, and demonstrated a 60% increase in body fat with reciprocal reductions in insulin sensitivity and glucose tolerance [31].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
What the sources say
- Not checked yetcites [31] Bäckhed F, Ding H, Wang T, Hooper LV, Koh GY, Nagy A, Semenkovich CF, Gordon JI (2004) The gut microbiota as an environmental factor that regulates fat storage. Proc Natl Acad Sci USA 101:15718–15723 source
boosteddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
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A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Gut microbiota, the bacteria, archaea, viruses, and eukaryotic microbes residing in the gastrointestinal tract are emerging as a potential contributor to age-associated muscle decline.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Abstract
hedgedconditional- Asserted: passes — The authors put it forward as true.
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In the paper
“Associated with these changes is a decrease in the integrity of epithelial tight junctions and increased intestinal permeability [14], facilitating the translocation of microbial byproducts into circulation.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Establishing an Aging Gut-Muscle Communication Axis
What the sources say
- Not checked yetcites [14] Thevaranjan N, Puchta A, Schulz C, Naidoo A, Szamosi JC, Verschoor CP, Loukov D, Schenck LP, Jury J, Foley KP, Schertzer JDL, Maggie J, Davidson DJ, Verd EF, Surette MG, Bowdish D (2017) Age-associated microbial dysbiosis promotes intestinal permeability, systemic inflammation, and macrophage dysfunction. Cell Host Microbe 21:455–466 source
plaincorrelational- Asserted: passes — The authors put it forward as true.
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In the paper
“exposure of myotubes to gut microbial-derived extracellular vesicles induces insulin resistance [30]”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
What the sources say
- Not checked yetcites [30] Choi Y, Kwon Y, Kim D-K, Jeon J, Jang SC, Wang T, Ban M, Kim M-H, Jeon SG, Kim M-S, Choi CS, Jee Y-K, Gho YS, Ryu SH, Kim Y-K (2015) Gut microbe-derived extracellular vesicles induce insulin resistance, thereby impairing glucose metabolism in skeletal muscle. Sci Rep 5:15878 source
plaindirect- Asserted: passes — The authors put it forward as true.
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In the paper
“circulating levels of lipopolysaccharide (LPS), a component of the outer membrane of gram negative bacteria, were 2- to-3-fold elevated in high-fat fed mice when compared with control fed animals.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
What the sources say
- Not checked yetcites [18] Cani PD, Amar J, Iglesias MA, Poggi M, Knauf C, Bastelica D, Neyrinck AM, Fava F, Tuohy KM, Chabo C, Ferrie J, Gibson GR, Casteilla L, Delzenne NM, Alessi MC (2007) Metabolic endotoxemia initiates obesity and insulin resistance. Diabetes 56:1761–1772 source
plaincorrelational- Asserted: passes — The authors put it forward as true.
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In the paper
“aging has been associated with alterations in myosin heavy chain (MHC) distribution [90].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Composition
What the sources say
- Not checked yetcites [90] Frontera WR, Hughes VA, Fielding RA, Fiatarone MA, Evans WJ (1985) Roubenoff R (2000) Aging of skeletal muscle: a 12-yr longitudinal study. J Appl Physiol 88:1321–1326 source
plaincorrelational- Asserted: passes — The authors put it forward as true.
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In the paper
“Regulation of muscle composition by gut microbiota is supported by associations between gut bacteria involved in energy metabolism and porcine intramuscular fat content [86].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Composition
What the sources say
- Not checked yetcites [86] Fang S, Xiong X, Su Y, Huang L, Chen C (2017) 16S rRNA gene-based association study identified microbial taxa associated with pork intramuscular fat content in feces and cecum lumen. BMC Microbiol 17:162 source
plaincorrelational- Asserted: passes — The authors put it forward as true.
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A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Taken together, these studies suggest a link between Lactobacillus species and skeletal muscle size that is worthy of further investigation in humans.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
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- Rests on an assumption: Findings from animal models (mice, rats, pigs) about gut microbiota and skeletal muscle can be generalized to humans.
In the paper
“L. acidophilus supplementation did not appear to affect inflammatory or atrophy markers [19].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [19] Bindels LB, Beck R, Schakman O, Martin JC, de Backer F, Sohet FM, Dewulf EM, Pachikian BD, Neyrinck AM, Thissen JP, Verrax J, Calderon PB, Pot B, Grangette C, Cani PD, Scott KP, Delzenne NM (2012) Restoring specific lactobacilli levels decreases inflammation and muscle atrophy markers in an acute leukemia mouse model. PLoS ONE 7:1–10 source
hedged- Asserted: passes — The authors put it forward as true.
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In the paper
“in vivo administration of indoxyl sulfate is shown to increase atrogene expression in conjunction with decreased muscle mass in mice [61].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [61] Enoki Y, Watanabe H, Arake R, Sugimoto R, Imafuku T, Tominaga Y, Ishima Y, Kotani S, Nakajima M, Tanaka M, Matsushita K, Fukagawa M, Otagiri M, Maruyama T (2016) Indoxyl sulfate potentiates skeletal muscle atrophy by inducing the oxidative stress-mediated expression of myostatin and atrogin-1. Sci Rep 6:32084 source
plaindirect- Asserted: passes — The authors put it forward as true.
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None of the sources cited for this claim have been checked yet.
In the paper
“studies in both animals and humans implicate IL-6 involvement in the repression of protein synthesis [58, 59].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [58] Haddad F, Zaldivar F, Cooper DM (1985) Adams GR (2005) IL-6-induced skeletal muscle atrophy. J Appl Physiol 98:911–917 source
- Not checked yetcites [59] Cuthbertson D, Smith K, Babraj J, Leese G, Waddell T, Atherton P, Wackerhage H, Taylor PM, Rennie MJ (2005) Anabolic signaling deficits underlie amino acid resistance of wasting, aging muscle. FASEB J 19:422–424 source
hedgedconditional- Asserted: passes — The authors put it forward as true.
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In the paper
“L. plantarum supplementation has demonstrated to increase lean mass and function (grip strength and swim time) in healthy young mice [63].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [63] Chen YM, Wei L, Chiu YS, Hsu YJ, Tsai TY, Wang MF, Huang CC (2016) Lactobacillus plantarum TWK10 supplementation improves exercise performance and increases muscle mass in mice. Nutrients 8:205 source
boosteddirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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In the paper
“Microbial profiling in these cachectic mice revealed gut dysbiosis characterized by selective modulation of Lactobacillus spp.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [19] Bindels LB, Beck R, Schakman O, Martin JC, de Backer F, Sohet FM, Dewulf EM, Pachikian BD, Neyrinck AM, Thissen JP, Verrax J, Calderon PB, Pot B, Grangette C, Cani PD, Scott KP, Delzenne NM (2012) Restoring specific lactobacilli levels decreases inflammation and muscle atrophy markers in an acute leukemia mouse model. PLoS ONE 7:1–10 source
plaincorrelational- Asserted: passes — The authors put it forward as true.
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None of the sources cited for this claim have been checked yet.
In the paper
“data showing butyrate (associated with Bifidobacterium [72]) treatment to protect against age-related muscle atrophy [73] supports the idea that pre- and/or probiotic supplementation, which is shown to increase the abundance of Bifidobacterium and butyrate producers in older individuals [74, 75], may prophylactically moderate aging muscle loss.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [72] Belenguer A, Duncan SH, Calder AG, Holtrop G, Louis P, Lobley GE, Flint HJ (2006) Two routes of metabolic cross-feeding between Bifidobacterium adolescentis and butyrate-producing anaerobes from the human gut. Appl Environ Microbiol 72:3593–3599 source
- Not checked yetcites [73] Walsh ME, Bhattacharya A, Sataranatarajan K, Qaisar R, Sloane L, Rahman MM, Kinter M, Van Remmen H (2015) The histone deacetylase inhibitor butyrate improves metabolism and reduces muscle atrophy during aging. Aging Cell 14:957–970 source
- Not checked yetcites [74] Eloe-Fadrosh EA, Brady A, Crabtree J, Drabek EF, Ma B, Mahurkar A, Ravel J, Haverkamp M, Fiorino AM, Botelho C, Andreyeva I, Hibberd PL, Fraser CM (2015) Functional dynamics of the gut microbiome in elderly people during probiotic consumption. MBio. doi: 10.1128/mBio.00231-15 source
- Not checked yetcites [75] Vulevic J, Drakoularakou A, Yaqoob P, Tzortzis G, Gibson GR (2008) Modulation of the fecal microflora profile and immune function by a novel trans-galactooligosaccharide mixture (B-GOS) in healthy elderly volunteers. Am J Clin Nutr 88:1438–1446 source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: Findings from animal models (mice, rats, pigs) about gut microbiota and skeletal muscle can be generalized to humans.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“As described throughout this review, these changes may manifest in older adults as decreases in muscle size and integrity that compromise physical function and ultimately detract from quality of life.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Establishing an Aging Gut-Muscle Communication Axis
hedgedconditional- Asserted: passes — The authors put it forward as true.
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In the paper
“the superior microbial milieu in exercise trained persons may explain lower levels of plasma endotoxin and inflammatory markers (plasminogen activator inhibitor type-1) in active vs sedentary individuals [104].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Function
What the sources say
- Not checked yetcites [104] Lira FS, Rosa JC, Pimentel GD, Souza HA, Caperuto EC, Carnevali LC, Seelaender M, Damaso AR, Oyama LM, de Mello MT, Santos RV (2010) Endotoxin levels correlate positively with a sedentary lifestyle and negatively with highly trained subjects. Lipids Health Dis 9:82 source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“These findings highlight the possibility that gut microbiota can transfer muscle fiber characteristics”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Composition
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: Findings from animal models (mice, rats, pigs) about gut microbiota and skeletal muscle can be generalized to humans.
None of the sources cited for this claim have been checked yet.
In the paper
“correlations between microbial diversity and cardiorespiratory fitness [102] in concert with the exercise training mediated rescue of high-fat diet-induced microbial disturbance [103] support the idea that exercise training may impart beneficial effects on gut health.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Function
What the sources say
- Not checked yetcites [102] Estaki M, Pither J, Baumeister P, Little JP, Gill SK, Ghosh S, Ahmadi-Vand Z, Marsden KR, Gibson DL (2016) Cardiorespiratory fitness as a predictor of intestinal microbial diversity and distinct metagenomic functions. Microbiome 4:42 source
- Not checked yetcites [103] Denou E, Marcinko K, Surette MG, Steinberg GR, Schertzer JD (2016) High-intensity exercise training increases the diversity and metabolic capacity of the mouse distal gut microbiota during diet-induced obesity. Am J Physiol Endocrinol Metab 310:E982–E993 source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“blood, circulating endotoxin promotes systemic inflammation that appears to trigger maladaptation of skeletal muscle.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Establishing an Aging Gut-Muscle Communication Axis
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: unclear — It is unclear why the paper says it holds.
In the paper
“prebiotic supplementation (inulin plus fructooligosaccharides) has been shown to increase muscle strength (handgrip) and endurance (exhaustion) in frail older adults [100]”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Function
What the sources say
- Not checked yetcites [100] Buigues C, Fernández-Garrido J, Pruimboom L, Hoogland AJ, Navarro-Martínez R, Martínez-Martínez M, Verdejo Y, Mascarós MC, Peris C, Cauli O (2016) Effect of a prebiotic formulation on frailty syndrome: a randomized, double-blind clinical trial. Int J Mol Sci 17:E392 source
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“LPS, the major component of the outer membrane of gram-negative bacteria that is found to be elevated in the circulation with aging [42].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Establishing an Aging Gut-Muscle Communication Axis
What the sources say
- Not checked yetcites [42] Ghosh S, Lertwattanarak R, Garduno Jde J, Galeana JJ, Li J, Zamarripa F, Lancaster JL, Mohan S, Hussey S, Musi N (2015) Elevated muscle TLR4 expression and metabolic endotoxemia in human aging. J Gerontol A Biol Sci Med Sci 70:232–246 source
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Once in the blood, circulating endotoxin promotes systemic inflammation that appears to trigger maladaptation of skeletal muscle.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Establishing an Aging Gut-Muscle Communication Axis
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“Upon stratifying subjects by frailty score, a unique bacterial signature characterized by marked reductions in Lactobacillus (~ 8-fold less) and commensurate increases in the quantity of Enterobacteriaceae (~ 6-fold more) in frail agers emerged.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Function
What the sources say
- Not checked yetcites [84] van Tongeren S, Slaets J, Harmsen H, Welling G (2005) Fecal microbiota composition and frailty. Appl Environ Microbiol 71:6438–6442 source
plaincorrelationaln = 23- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“metagenomics findings in a larger sample of older adults (n = 178; ~ 78 years) [98] demonstrating that community-dwelling elders had more butyrate-producing microbes than those in long-stay residence.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Function
What the sources say
- Not checked yetcites [98] Claesson MJ, Jeffery IB, Conde S, Power SE, O’Connor EM, Cusack S, Harris HMB, Coakley M, Lakshminarayanan B, O’Sullivan O, Fitzgerald GF, Deane J, O’Connor M, Harnedy N, O’Connor K, O’Mahony D, van Sinderen D, Wallace M, Brennan L, Stanton C, Marchesi JR, Fitzgerald AP, Shanahan F, Hill C, Ross RP, O’Toole PW (2012) Gut microbiota composition correlates with diet and health in the elderly. Nature 9:178–184 source
boostedcorrelationaln = 178- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“This relationship is exemplified by commensurate changes in gut health and skeletal muscle with aging.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Perspectives and Steps Forward
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: unclear — It is unclear why the paper says it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Although this field is still in its infancy, the data presented here provide evidence to suggest a bidirectional communication network between gut microbiota and skeletal muscle.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Perspectives and Steps Forward
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“higher functioning subjects may have been protected from dysbiotic shifts in gut microbiota by a greater abundance of butyrate-producing bacteria such as Faecalibacterium prausnitzii.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Function
hedgedconditionaln = 23- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“We propose regulation of skeletal muscle by gut microbiota to occur in an endocrine manner, beginning with a disturbance in gut homeostasis and culminating with alterations in skeletal muscle characteristics.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Establishing an Aging Gut-Muscle Communication Axis
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: Findings from animal models (mice, rats, pigs) about gut microbiota and skeletal muscle can be generalized to humans.
- It may state two separate claims as one. 36
- Probably not a substantial claim. 7
Every source the paper cites for this claim was checked and supports it.
In the paper
“associations between gut ecology and cancer [16], cardiovascular disease [17], obesity [6], diabetes [18], and muscle wasting [19]”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Introduction
What the sources say
- Supportedcites [16] Yu LX, Yan HX, Liu Q, Yang W, Wu HP, Dong W, Tang L, Lin Y, He YQ, Zou SS, Wang C, Zhang HL, Cao GW, Wu MC, Wang HY (2010) Endotoxin accumulation prevents carcinogen-induced apoptosis and promotes liver tumorigenesis in rodents. Hepatology 52:1322–1333 source
Citation [16] is attached to cancer, not to the other listed conditions. The paper’s Discussion links gut-derived endotoxin to liver tumor development, and its opening summary reports that reducing endotoxin or disabling its receptor reduced carcinogen-induced liver tumors in rodents. (LLM, conf=0.92)
- Supportedcites [17] Tang WH, Wang Z, Levison BS, Koeth RA, Britt EB, Fu X, Wu Y, Hazen SL (2013) Intestinal microbial metabolism of phosphatidylcholine and cardiovascular risk. N Engl J Med 368:1575–1584 source
The citation [17] is attached only to cardiovascular disease, not to the other conditions in the sentence. The Discussion reports that the intestinal microbiota-dependent metabolite TMAO predicts incident major adverse cardiovascular events and suggests a role for microbiota-dependent pathways in coronary artery disease. (LLM, conf=0.93)
- Supportedcites [19] Bindels LB, Beck R, Schakman O, Martin JC, de Backer F, Sohet FM, Dewulf EM, Pachikian BD, Neyrinck AM, Thissen JP, Verrax J, Calderon PB, Pot B, Grangette C, Cani PD, Scott KP, Delzenne NM (2012) Restoring specific lactobacilli levels decreases inflammation and muscle atrophy markers in an acute leukemia mouse model. PLoS ONE 7:1–10 source
Citation [19] is attached to muscle wasting, not to the other conditions in the sentence. The Discussion reports that, in an acute leukemia mouse model, lower levels of specific gut lactobacilli were associated with muscle atrophy markers. This supports the cited association within that model. (LLM, conf=0.92)
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Supported
None of the sources cited for this claim have been checked yet.
In the paper
“high-fat feeding is shown to compromise epithelial tight junctions and increase intestinal permeability [34, 35]”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
What the sources say
- Not checked yetcites [34] Gulhane M, Murray L, Lourie R, Tong H, Sheng YH, Wang R, Kang A, Schreiber V, Wong KY, Magor G, Denman S, Begun J, Florin TH, Perkins A, Cuiv PO, McGuckin MA, Hasnain SZ (2016) High fat diets induce colonic epithelial cell stress and inflammation that is reversed by IL-22. Sci Rep 6:28990 source
- Not checked yetcites [35] Guo S, Al-Sadi R, Said HM, Ma TY (2013) Lipopolysaccharide causes an increase in intestinal tight junction permeability in vitro and in vivo by inducing enterocyte membrane expression and localization of TLR-4 and CD14. Am J Pathol 182:375–387 source
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“high-fat diet, which is known to induce chronic low-grade chronic inflammation (e.g., IL-1, IL-6, and TNF-α elevation), a reported contributor to insulin resistance [32, 33].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
What the sources say
- Not checked yetcites [32] Hotamisligil GS, Peraldi P, Budavari A, Ellis R, White MF, Spiegelman BM (1996) IRS-1-mediated inhibition of insulin receptor tyrosine kinase activity in TNF-alpha- and obesity-induced insulin resistance. Science 271:665–668 source
- Not checked yetcites [33] Senn JJ, Klover PJ, Nowak IA, Mooney RA (2002) Interleukin-6 induces cellular insulin resistance in hepatocytes. Diabetes 51:3391–3399 source
boosteddirect- Asserted: passes — The authors put it forward as true.
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Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
In the paper
“As expected, high-fat fed mice exhibited an increase in body weight and inflammatory markers as well as a decrease in glucose tolerance.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
What the sources say
- Not checked yetcites [18] Cani PD, Amar J, Iglesias MA, Poggi M, Knauf C, Bastelica D, Neyrinck AM, Fava F, Tuohy KM, Chabo C, Ferrie J, Gibson GR, Casteilla L, Delzenne NM, Alessi MC (2007) Metabolic endotoxemia initiates obesity and insulin resistance. Diabetes 56:1761–1772 source
plaindirect- Asserted: passes — The authors put it forward as true.
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In the paper
“Endotoxin-mediated reductions in glucose tolerance have been similarly shown in humans inoculated with LPS, as evidenced by significant increases in skeletal muscle NF-κβ binding activity and JNK phosphorylation, which synergistically inhibit insulin signaling [36].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
What the sources say
- Not checked yetcites [36] Aguirre V, Uchida T, Yenush L, Davis R, White MF (2000) The c-Jun NH(2)-terminal kinase promotes insulin resistance during association with insulin receptor substrate-1 and phosphorylation of Ser(307). J Biol Chem 275:9047–9054 source
plaindirect- Asserted: passes — The authors put it forward as true.
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None of the sources cited for this claim have been checked yet.
In the paper
“The composition of gut microbiota is shown to be dynamic throughout the lifespan, undergoing rapid changes from birth until ~ 3 years of age, after which greater stability is established [11, 12].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Introduction
What the sources say
- Not checked yetcites [11] Yatsunenko T, Rey FE, Manary MJ, Trehan I, Dominguez-Bello MG, Contreras M, Magris M, Hidalgo G, Baldassano RN, Anokhin AP, Heath AC, Warner B, Reeder J, Kuczynski J, Caporaso JG, Lozupone CA, Lauber C, Clemente JC, Knights D, Knight R, Gordon JI (2012) Human gut microbiome viewed across age and geography. Nature 486:222–227 source
- Not checked yetcites [12] Hill CJ, Lynch DB, Murphy K, Ulaszewska M, Jeffery IB, O’Shea C, Watkins C, Dempsey E, Mattivi F, Tuohy K, Ross RP, Ryan CA, O’Toole P, Stanton C (2017) Evolution of gut microbiota composition from birth to 24 weeks in the INFANTMET Cohort. Microbiome 5:4 source
plain- Asserted: passes — The authors put it forward as true.
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Probably not a substantial claim. The paper’s conclusions may not depend on it.
In the paper
“in older individuals circulating LPS and skeletal muscle TLR4 (a receptor for LPS [43]) gene expression and protein content were higher, and insulin sensitivity (quantified by HOMA-IR) was lower than their younger counterparts.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
What the sources say
- Not checked yetcites [42] Ghosh S, Lertwattanarak R, Garduno Jde J, Galeana JJ, Li J, Zamarripa F, Lancaster JL, Mohan S, Hussey S, Musi N (2015) Elevated muscle TLR4 expression and metabolic endotoxemia in human aging. J Gerontol A Biol Sci Med Sci 70:232–246 source
plaincorrelational- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“Gut microbiota are emerging as a salient contributor to human health and disease [5], and their effects are particularly pronounced in older years [20].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Introduction
What the sources say
plaincorrelational- Asserted: passes — The authors put it forward as true.
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Probably not a substantial claim. It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“These studies and others [30, 37], show that circulating LPS, a prominent component of gut microbiota, induces skeletal muscle inflammation and insulin resistance thereby contributing to the development of metabolic syndrome.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
What the sources say
- Not checked yetcites [30] Choi Y, Kwon Y, Kim D-K, Jeon J, Jang SC, Wang T, Ban M, Kim M-H, Jeon SG, Kim M-S, Choi CS, Jee Y-K, Gho YS, Ryu SH, Kim Y-K (2015) Gut microbe-derived extracellular vesicles induce insulin resistance, thereby impairing glucose metabolism in skeletal muscle. Sci Rep 5:15878 source
- Not checked yetcites [37] Liang H, Hussey SE, Sanchez-Avila A, Tantiwong P, Musi N (2013) Effect of lipopolysaccharide on inflammation and insulin action in human muscle. PLoS ONE 8:e63983 source
plaindirect- Asserted: passes — The authors put it forward as true.
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None of the sources cited for this claim have been checked yet.
In the paper
“in response to the gut microbiota-specific metabolite indoxyl sulfate [38], C2C12 myoblasts exhibit an up-regulation of glycolysis and an increase in the activity of the pentose phosphate pathway [39].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Metabolism
What the sources say
- Not checked yetcites [38] Wikoff WR, Anfora AT, Liu J, Schultz PG, Lesley SA, Peters EC, Siuzdak G (2009) Metabolomics analysis reveals large effects of gut microflora on mammalian blood metabolites. Proc Natl Acad Sci USA 106:3698–3703 source
- Not checked yetcites [39] Sato E, Mori T, Mishima E, Suzuki A, Sugawara S, Kurasawa N, Saigusa D, Miura D, Morikawa-Ichinose T, Saito R, Oba-Yabana I, Oe Y, Kisu K, Naganuma E, Koizumi K, Mokudai T, Niwano Y, Kudo T, Suzuki C, Takahashi N, Sato H, Abe T, Niwa T, Ito S (2016) Metabolic alterations by indoxyl sulfate in skeletal muscle induce uremic sarcopenia in chronic kidney disease. Sci Rep 6:36618 source
plaindirect- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“TNF-α and IL-6 are strongly induced by circulating LPS [53] and elevated in aging individuals [54, 55].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [53] Frost RA, Nystrom GJ, Lang CH (2002) Lipopolysaccharide regulates proinflammatory cytokine expression in mouse myoblasts and skeletal muscle. Am J Physiol Regul Integr Comp Physiol 283:R698–R709 source
- Not checked yetcites [54] Bruunsgaard H, Andersen-Ranberg K, Jeune B, Pedersen AN, Skinhoj P, Pedersen BK (1999) A high plasma concentration of TNF-alpha is associated with dementia in centenarians. J Gerontol A Biol Sci Med Sci 54:M357–M364 source
- Not checked yetcites [55] Maggio M, Guralnik JM, Longo DL, Ferrucci L (2006) Interleukin-6 in aging and chronic disease: a magnificent pathway. J Gerontol A Biol Sci Med Sci 61:575–584 source
boosteddirect- Asserted: passes — The authors put it forward as true.
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None of the sources cited for this claim have been checked yet.
In the paper
“adipose tissue infiltration in skeletal muscle (i.e., change in muscle composition) has been shown to increase with age [81] and is associated with mobility impairment [82].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Composition
What the sources say
- Not checked yetcites [81] Goodpaster BH, Carlson CL, Visser M, Kelley DE, Scherzinger A, Harris TB, Stamm E (1985) Newman AB (2001) Attenuation of skeletal muscle and strength in the elderly: the health ABC study. J Appl Physiol 90:2157–2165 source
- Not checked yetcites [82] Visser M, Kritchevsky SB, Goodpaster BH, Newman AB, Nevitt M, Stamm E, Harris TB (2002) Leg muscle mass and composition in relation to lower extremity performance in men and women aged 70 to 79: the health, aging and body composition study. J Am Geriatr Soc 50:897–904 source
plaincorrelational- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Coupling of these microbial alterations with restoration of intestinal homeostasis (e.g., increase tight junction proteins) and a reduction in muscle wasting suggests that Lactobacillus and Bifidobacterium may influence gut-muscle communication and regulate muscle size.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
hedgedconditional- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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It may state two separate claims as one.
- Rests on an assumption: Findings from animal models (mice, rats, pigs) about gut microbiota and skeletal muscle can be generalized to humans.
In the paper
“the authors reported an increase in circulating inflammatory cytokines (IL-6, TNF-α, and MCP-1) and intramuscular fat after just 3 days [85]”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Composition
What the sources say
- Not checked yetcites [85] Collins KH, Paul HA, Hart DA, Reimer RA, Smith IC, Rios JL, Seerattan RA, Herzog W (2016) A high-fat high-sucrose diet rapidly alters muscle integrity, inflammation and gut microbiota in male rats. Sci Rep 6:37278 source
plaindirect- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“the tryptophan derivative indoxyl sulfate, which is similarly shown to increase with age [60], is reported to induce inflammatory cytokine expression (IL-6 and TNF-α) and markers of muscle atrophy (myostatin and atrogin-1) similar to that of LPS in cultured myocytes [61].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [60] Wyczalkowska-Tomasik A, Czarkowska-Paczek B, Giebultowicz J, Wroczynski P, Paczek L (2017) Age-dependent increase in serum levels of indoxyl sulphate and p-cresol sulphate is not related to their precursors: tryptophan and tyrosine. Geriatr Gerontol Int 17:1022–1026 source
- Not checked yetcites [61] Enoki Y, Watanabe H, Arake R, Sugimoto R, Imafuku T, Tominaga Y, Ishima Y, Kotani S, Nakajima M, Tanaka M, Matsushita K, Fukagawa M, Otagiri M, Maruyama T (2016) Indoxyl sulfate potentiates skeletal muscle atrophy by inducing the oxidative stress-mediated expression of myostatin and atrogin-1. Sci Rep 6:32084 source
plaindirect- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
In the paper
“sepsis, a life-threatening illness characterized by severe muscle wasting due to both increases in proteolytic degradation and reductions in protein synthesis [52].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [52] Callahan LA, Supinski GS (2009) Sepsis-induced myopathy. Crit Care Med 37:S354–S367 source
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: fails — The paper’s conclusions may not depend on it.
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Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
In the paper
“obesity appears to exacerbate the progression of sarcopenia by compounding inflammatory burden [45], resulting in a state of sarcopenic obesity”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [45] Cesari M, Kritchevsky SB, Baumgartner RN, Atkinson HH, Penninx BW, Lenchik L, Palla SL, Ambrosius WT, Tracy RP, Pahor M (2005) Sarcopenia, obesity, and inflammation–results from the trial of angiotensin converting enzyme inhibition and novel cardiovascular risk factors study. Am J Clin Nutr 82:428–434 source
hedgedconditional- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
In the paper
“Follow-up analyses confirmed the favorable effect of prebiotic feeding on gut microbiota, as was evidenced by a shift in the ratio of Bacteroidetes/Firmicutes in addition to increases in the levels of Lactobacillus and Bifidobacterium spp. [66].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [66] Everard A, Lazarevic V, Derrien M, Girard M, Muccioli GG, Neyrinck AM, Possemiers S, Van Holle A, Francois P, de Vos WM, Delzenne NM, Schrenzel J, Cani PD (2011) Responses of gut microbiota and glucose and lipid metabolism to prebiotics in genetic obese and diet-induced leptin-resistant mice. Diabetes 60:2775–2786 source
boosteddirect- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“A variety of phenomena have been proposed to contribute to this age-related heightened inflammatory state including redox stress [46], immuno- and endocrine senescence [47, 48], DNA damage [49], epigenetic modification [50], and a distortion of gut microbial homeostasis [51] that is associated with increased levels of circulating endotoxin [42].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [46] Sohal RS, Orr WC (2012) The redox stress hypothesis of aging. Free Radic Biol Med 52:539–555 source
- Not checked yetcites [47] Franceschi C, Bonafe M, Valensin S (2000) Human immunosenescence: the prevailing of innate immunity, the failing of clonotypic immunity, and the filling of immunological space. Vaccine 18:1717–1720 source
- Not checked yetcites [48] Maggio M, Basaria S, Ble A, Lauretani F, Bandinelli S, Ceda GP, Valenti G, Ling SM, Ferrucci L (2006) Correlation between testosterone and the inflammatory marker soluble interleukin-6 receptor in older men. J Clin Endocrinol Metab 91:345–347 source
- Not checked yetcites [51] Cevenini E, Caruso C, Candore G, Capri M, Nuzzo D, Duro G, Rizzo C, Colonna-Romano G, Lio D, Di Carlo D, Palmas MG, Scurti M, Pini E, Franceschi C, Vasto S (2010) Age-related inflammation: the contribution of different organs, tissues and systems. How to face it for therapeutic approaches. Curr Pharm Des 16:609–618 source
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. It may state two separate claims as one.
In the paper
“an age-related decrease in gut Bifidobacterium content may underlie increases in circulating endotoxin that are shown to induce skeletal muscle atrophy [71].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [71] Morales MG, Olguin H, Di Capua G, Brandan E, Simon F, Cabello-Verrugio C (2015) Endotoxin-induced skeletal muscle wasting is prevented by angiotensin-(1-7) through a p38 MAPK-dependent mechanism. Clin Sci (Lond) 129:461–476 source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: Findings from animal models (mice, rats, pigs) about gut microbiota and skeletal muscle can be generalized to humans.
None of the sources cited for this claim have been checked yet.
In the paper
“Macrophage production of TNF-α is shown to occur early in the stress response, and has been demonstrated to stimulate protein degradation and apoptosis in cultured cells [56, 57].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [56] Li YP, Chen Y, John J, Moylan J, Jin B, Mann DL, Reid MB (2005) TNF-alpha acts via p38 MAPK to stimulate expression of the ubiquitin ligase atrogin1/MAFbx in skeletal muscle. FASEB J 19:362–370 source
- Not checked yetcites [57] Baxter GT, Kuo RC, Jupp OJ, Vandenabeele P, MacEwan DJ (1999) Tumor necrosis factor-alpha mediates both apoptotic cell death and cell proliferation in a human hematopoietic cell line dependent on mitotic activity and receptor subtype expression. J Biol Chem 274:9539–9547 source
boosteddirect- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“Bifidobacterium are shown to decrease with age [68], and are associated with lower intestinal [69] and circulating LPS levels [70].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [68] Enck P, Zimmermann K, Rusch K, Schwiertz A, Klosterhalfen S, Frick JS (2009) The effects of ageing on the colonic bacterial microflora in adults. Z Gastroenterol 47:653–658 source
- Not checked yetcites [69] Griffiths EA, Duffy LC, Schanbacher FL, Qiao H, Dryja D, Leavens A, Rossman J, Rich G, Dirienzo D, Ogra PL (2004) In vivo effects of bifidobacteria and lactoferrin on gut endotoxin concentration and mucosal immunity in Balb/c mice. Dig Dis Sci 49:579–589 source
- Not checked yetcites [70] Cani PD, Neyrinck AM, Fava F, Knauf C, Burcelin RG, Tuohy KM, Gibson GR, Delzenne NM (2007) Selective increases of bifidobacteria in gut microflora improve high-fat-diet-induced diabetes in mice through a mechanism associated with endotoxaemia. Diabetologia 50:2374–2383 source
plaincorrelational- Asserted: passes — The authors put it forward as true.
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- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“Collins et al. subjected young rats to a high-fat high-sucrose diet and found an increase in Enterobacteriaceae (gram-negative member of the Proteobacteria phylum) and a decrease in the abundance of Lactobacillus spp., changes that have been similarly reported with aging [83, 84].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Composition
What the sources say
- Not checked yetcites [83] Biagi E, Nylund L, Candela M, Ostan R, Bucci L, Pini E, Nikkila J, Monti D, Satokari R, Franceschi C, Brigidi P, De Vos W (2010) Through ageing, and beyond: gut microbiota and inflammatory status in seniors and centenarians. PLoS ONE 5:e10667 source
- Not checked yetcites [84] van Tongeren S, Slaets J, Harmsen H, Welling G (2005) Fecal microbiota composition and frailty. Appl Environ Microbiol 71:6438–6442 source
plaindirect- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“aging muscle appears to undergo a fast-to-slow fiber-type shift [91], that is hypothesized to reduce whole muscle power and increase fall risk [92, 93].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Composition
What the sources say
- Not checked yetcites [91] Larsson L, Grimby G, Karlsson J (1979) Muscle strength and speed of movement in relation to age and muscle morphology. J Appl Physiol Respir Environ Exerc Physiol 46:451–456
- Not checked yetcites [92] Korhonen MT, Cristea A, Alen M, Hakkinen K, Sipila S, Mero A, Viitasalo JT, Larsson L (1985) Suominen H (2006) Aging, muscle fiber type, and contractile function in sprint-trained athletes. J Appl Physiol 101:906–917 source
- Not checked yetcites [93] Reid KF, Fielding RA (2012) Skeletal muscle power: a critical determinant of physical functioning in older adults. Exerc Sport Sci Rev 40:4–12 source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
In the paper
“administration of a synbiotic containing inulin-type fructans and Lactobacillus reuteri was shown to reverse increases in Escherichia and promoted proliferation of Lactobacillus and Bifidobacterium in leukaemic mice [67].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [67] Bindels LB, Neyrinck AM, Claus SP, Le Roy CI, Grangette C, Pot B, Martinez I, Walter J, Cani PD, Delzenne NM (2016) Synbiotic approach restores intestinal homeostasis and prolongs survival in leukaemic mice with cachexia. ISME J 10:1456–1470 source
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“these findings demonstrate the ability of LPS-associated cytokines to determinately affect protein equilibrium (i.e., synthesis and breakdown), and suggest that elevated endotoxin levels with age may contribute to reductions in muscle mass.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“Cani et al., who showed a decrease in circulating LPS and inflammation and an increase in muscle mass in obese mice fed the prebiotic fiber oligofructose [65].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [65] Cani PD, Possemiers S, Van de Wiele T, Guiot Y, Everard A, Rottier O, Geurts L, Naslain D, Neyrinck A, Lambert DM, Muccioli GG, Delzenne NM (2009) Changes in gut microbiota control inflammation in obese mice through a mechanism involving GLP-2-driven improvement of gut permeability. Gut 58:1091–1103 source
boosteddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“the leukemic mice were given an oral probiotic containing Lactobacillus reuteri and L. gasseri that appeared to decrease serum levels of inflammatory cytokines (IL-6 and MCP-1) and atrogene expression (MuRF1 and Atrogin-1) in conjunction with an increase in mass of the tibialis anterior.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Size
What the sources say
- Not checked yetcites [19] Bindels LB, Beck R, Schakman O, Martin JC, de Backer F, Sohet FM, Dewulf EM, Pachikian BD, Neyrinck AM, Thissen JP, Verrax J, Calderon PB, Pot B, Grangette C, Cani PD, Scott KP, Delzenne NM (2012) Restoring specific lactobacilli levels decreases inflammation and muscle atrophy markers in an acute leukemia mouse model. PLoS ONE 7:1–10 source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“Age-related changes in skeletal muscle size and composition summate to yield reductions in skeletal muscle function (strength and power) [77] that ultimately affect physical performance and the ability to live independently [95].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Function
What the sources say
- Not checked yetcites [77] Reid KF, Naumova EN, Carabello RJ, Phillips EM, Fielding RA (2008) Lower extremity muscle mass predicts functional performance in mobility-limited elders. J Nutr Health Aging 12:493–498 source
- Not checked yetcites [95] Bean JF, Leveille SG, Kiely DK, Bandinelli S, Guralnik JM, Ferrucci L (2003) A comparison of leg power and leg strength within the InCHIANTI study: which influences mobility more? J Gerontol A Biol Sci Med Sci 58:728–733 source
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“Comparison of microbial diversity among these athletes and both healthy normal weight (BMI ≤ 25) and overweight (BMI ≥ 28) age-matched controls elicited a hierarchical pattern (athletes > healthy > overweight), suggesting an association between microbial diversity, body composition, and physical function.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Function
What the sources say
- Not checked yetcites [101] Clarke SF, Murphy EF, O’Sullivan O, Lucey AJ, Humphreys M, Hogan A, Hayes P, O’Reilly M, Jeffery IB, Wood-Martin R, Kerins DM, Quigley E, Ross RP, O’Toole PW, Molloy MG, Falvey E, Shanahan F, Cotter PD (2014) Exercise and associated dietary extremes impact on gut microbial diversity. Gut 63:1913–1920 source
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“transfer of gut microbiota from an obese pig to a GF mouse replicated the host myocellular phenotype, which mirrored that of aging skeletal muscle (i.e., fast fiber atrophy concomitant with a fast-to-slow fiber type shift).”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Composition
What the sources say
- Not checked yetcites [94] Yan H, Diao H, Xiao Y, Li W, Yu B, He J, Yu J, Zheng P, Mao X, Luo Y, Zeng B, Wei H, Chen D (2016) Gut microbiota can transfer fiber characteristics and lipid metabolic profiles of skeletal muscle from pigs to germ-free mice. Sci Rep 6:31786 source
plaindirectSingle case- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The beneficial changes in gut health seen with exercise training implicate skeletal muscle contraction as a regulator of microbial composition, and provide evidence for bi-directional gut-muscle effects.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Function
hedgeddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“butyrate is shown to enhance intestinal barrier function by reinforcing tight junction assembly [96], which, in theory, should prevent endotoxin translocation and reduce circulating inflammation [97].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Function
What the sources say
- Not checked yetcites [96] Peng L, Li ZR, Green RS, Holzman IR, Lin J (2009) Butyrate enhances the intestinal barrier by facilitating tight junction assembly via activation of AMP-activated protein kinase in Caco-2 cell monolayers. J Nutr 139:1619–1625 source
- Not checked yetcites [97] Cox MA, Jackson J, Stanton M, Rojas-Triana A, Bober L, Laverty M, Yang X, Zhu F, Liu J, Wang S, Monsma F, Vassileva G, Maguire M, Gustafson E, Bayne M, Chou CC, Lundell D, Jenh CH (2009) Short-chain fatty acids act as antiinflammatory mediators by regulating prostaglandin E(2) and cytokines. World J Gastroenterol 15:5549–5557 source
hedgeddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“investigations of age-related changes in gut microbiota describe a bacterial community that is both less diverse and lacking in microorganisms responsible for the production of butyrate (indicative of gastrointestinal health) [15, 84, 98, 99], and more abundant in pathogens belonging to the Proteobacteria phylum (e.g., Enterobacteriaceae) [15, 68, 83].”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Establishing an Aging Gut-Muscle Communication Axis
What the sources say
- Not checked yetcites [15] Rampelli S, Candela M, Turroni S, Collino EB, Franceschi C, O’Toole PW, Brigidi P (2013) Functional metagenomic profiling of intestinal microbiome in extreme ageing. Aging 5:902–912 source
- Not checked yetcites [84] van Tongeren S, Slaets J, Harmsen H, Welling G (2005) Fecal microbiota composition and frailty. Appl Environ Microbiol 71:6438–6442 source
- Not checked yetcites [98] Claesson MJ, Jeffery IB, Conde S, Power SE, O’Connor EM, Cusack S, Harris HMB, Coakley M, Lakshminarayanan B, O’Sullivan O, Fitzgerald GF, Deane J, O’Connor M, Harnedy N, O’Connor K, O’Mahony D, van Sinderen D, Wallace M, Brennan L, Stanton C, Marchesi JR, Fitzgerald AP, Shanahan F, Hill C, Ross RP, O’Toole PW (2012) Gut microbiota composition correlates with diet and health in the elderly. Nature 9:178–184 source
- Not checked yetcites [99] Jeffery IB, Lynch DB, O’Toole PW (2016) Composition and temporal stability of the gut microbiota in older persons. ISME J 10:170–182 source
- Not checked yetcites [68] Enck P, Zimmermann K, Rusch K, Schwiertz A, Klosterhalfen S, Frick JS (2009) The effects of ageing on the colonic bacterial microflora in adults. Z Gastroenterol 47:653–658 source
- Not checked yetcites [83] Biagi E, Nylund L, Candela M, Ostan R, Bucci L, Pini E, Nikkila J, Monti D, Satokari R, Franceschi C, Brigidi P, De Vos W (2010) Through ageing, and beyond: gut microbiota and inflammatory status in seniors and centenarians. PLoS ONE 5:e10667 source
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“Associated with these changes is a decrease in the integrity of epithelial tight junctions and increased intestinal permeability [14], facilitating the translocation of microbial byproducts into circulation.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Establishing an Aging Gut-Muscle Communication Axis
What the sources say
- Not checked yetcites [14] Thevaranjan N, Puchta A, Schulz C, Naidoo A, Szamosi JC, Verschoor CP, Loukov D, Schenck LP, Jury J, Foley KP, Schertzer JDL, Maggie J, Davidson DJ, Verd EF, Surette MG, Bowdish D (2017) Age-associated microbial dysbiosis promotes intestinal permeability, systemic inflammation, and macrophage dysfunction. Cell Host Microbe 21:455–466 source
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Research in murine models has begun to identify microbial targets with likely skeletal muscle ramifications.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Perspectives and Steps Forward
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: fails — The paper may give no reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“these findings advocate that exercise training is an effective means to promote beneficial changes in gut microbial health that seem to reduce circulating inflammation and support the maintenance of muscle mass and function.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Function
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: Findings from animal models (mice, rats, pigs) about gut microbiota and skeletal muscle can be generalized to humans.
In the paper
“institutionalized elderly had a greater abundance of Enterobacteriaceae and Escherichia/Shigella, and less gut microbial diversity when compared with the community dwellers.”
§ Gut Microbiota Contribute to Age-Related Changes in Skeletal Muscle Size, Composition, and Function: Biological Basis for a Gut-Muscle Axis > Gut Microbiota and Skeletal Muscle Size, Composition, and Function > Muscle Function
What the sources say
- Not checked yetcites [98] Claesson MJ, Jeffery IB, Conde S, Power SE, O’Connor EM, Cusack S, Harris HMB, Coakley M, Lakshminarayanan B, O’Sullivan O, Fitzgerald GF, Deane J, O’Connor M, Harnedy N, O’Connor K, O’Mahony D, van Sinderen D, Wallace M, Brennan L, Stanton C, Marchesi JR, Fitzgerald AP, Shanahan F, Hill C, Ross RP, O’Toole PW (2012) Gut microbiota composition correlates with diet and health in the elderly. Nature 9:178–184 source
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
The paper relies on this without support.
Findings from animal models (mice, rats, pigs) about gut microbiota and skeletal muscle can be generalized to humans.
“Taken together, these studies suggest a link between Lactobacillus species and skeletal muscle size that is worthy of further investigation in humans.”
“These findings highlight the possibility that gut microbiota can transfer muscle fiber characteristics, and open the door for studies investigating the transplant of microbiota from young to old as a means to improve skeletal muscle size and composition.”
The paper relies on this without support.
Age-related changes in gut microbiota observed in cross-sectional studies reflect aging rather than cohort or environmental differences.
“Although the underlying cause(s) (host vs environment) of this apparent age-related microbial imbalance have yet to be defined”
“While changes in gut microbiota can be attributed to either host (genetics, age) or environmental (activity, diet) factors, we have focused on microbial dynamics with organismal aging.”
The paper relies on this without support.
Microbial targets identified in murine models have ramifications for human skeletal muscle.
“Research in murine models has begun to identify microbial targets with likely skeletal muscle ramifications.”
“These findings lay the framework for strategic human interventions aiming to manipulate microbial ecology as a means to benefit skeletal muscle health and extend healthy life years in a rapidly expanding aging population.”
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
In the citing paper
“This endotoxin leads to systemic inflammation which affects the skeletal muscle, affecting its integrity [17].”
From Novel Insights on Intake of Fish and Prevention of Sarcopenia: All Reasons for an Adequate Consumption (2020) · cites this paper as [17]
Citations
Cites
Diversity of the Human Intestinal Microbial Flora
Eckburg, P. B., Bik, E. M., Bernstein, C. N., Purdom, E., Dethlefsen, L., Sargent, M., Gill, S. R., Nelson, K. E., & Relman, D. A. (2005) · Science · doi:10.1126/science.1110591 · Cited by 7,913
A core gut microbiome in obese and lean twins
Turnbaugh, P. J., Hamady, M., Yatsunenko, T., Cantarel, B. L., Duncan, A., Ley, R. E., Sogin, M. L., Jones, W. J., Roe, B. A., Affourtit, J. P., et al. (2009) · Nature · doi:10.1038/nature07540 · Cited by 7,823
Human gut microbiome viewed across age and geography
Yatsunenko, T., Rey, F. E., Manary, M. J., Trehan, I., Dominguez-Bello, M. G., Contreras, M., Magris, M., Hidalgo, G., Baldassano, R. N., Anokhin, A. P., et al. (2012) · Nature · doi:10.1038/nature11053 · Cited by 7,815
Metabolic Endotoxemia Initiates Obesity and Insulin Resistance
Cani, P. D., Amar, J., Iglesias, M. A., Poggi, M., Knauf, C., Bastelica, D., Neyrinck, A. M., Fava, F., Tuohy, K. M., Chabo, C., et al. (2007) · Diabetes · doi:10.2337/db06-1491 · Cited by 6,638
The gut microbiota as an environmental factor that regulates fat storage
Bäckhed, F., Ding, H., Wang, T., Hooper, L. V., Koh, G. Y., Nagy, A., Semenkovich, C. F., & Gordon, J. I. (2004) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0407076101 · Cited by 6,245
Turnbaugh, P. J., Ley, R. E., Hamady, M., Fraser-Liggett, C. M., Knight, R., & Gordon, J. I. (2007) · Nature · doi:10.1038/nature06244 · Cited by 6,091
Revised Estimates for the Number of Human and Bacteria Cells in the Body
Sender, R., Fuchs, S., & Milo, R. (2016) · PLOS Biology · doi:10.1371/journal.pbio.1002533 · Cited by 5,425
Richness of human gut microbiome correlates with metabolic markers
Le Chatelier, E., Nielsen, T., Qin, J., Prifti, E., Hildebrand, F., Falony, G., Almeida, M., Arumugam, M., Batto, J.-M., Kennedy, S., et al. (2013) · Nature · doi:10.1038/nature12506 · Cited by 4,662
Gut Microbiota from Twins Discordant for Obesity Modulate Metabolism in Mice
Ridaura, V. K., Faith, J. J., Rey, F. E., Cheng, J., Duncan, A. E., Kau, A. L., Griffin, N. W., Lombard, V., Henrissat, B., Bain, J. R., et al. (2013) · Science · doi:10.1126/science.1241214 · Cited by 3,788
Intestinal microbial metabolism of phosphatidylcholine and cardiovascular risk
Tang, W. H. W., Wang, Z., Levison, B. S., Koeth, R. A., Britt, E. B., Fu, X., Wu, Y., & Hazen, S. L. (2013) · New England Journal of Medicine · doi:10.1056/nejmoa1109400 · Cited by 3,400
Cited by
Sorted by citations
Inflammaging: a new immune–metabolic viewpoint for age-related diseases
Franceschi, C., Garagnani, P., Parini, P., Giuliani, C., & Santoro, A. (2018) · Nature Reviews Endocrinology · doi:10.1038/s41574-018-0059-4 · Cited by 3,586
The double burden of malnutrition: aetiological pathways and consequences for health
Wells, J. C., Sawaya, A. L., Wibaek, R., Mwangome, M., Poullas, M. S., Yajnik, C. S., & Demaio, A. (2020) · The Lancet · doi:10.1016/s0140-6736(19)32472-9 · Cited by 993
Wang, X., Tsai, T.-C., Deng, F., Wei, X., Chai, J., Knapp, J., APPLE, J. K., Maxwell, C. V. V., Lee, J. A., Li, Y., et al. (2019) · Microbiome · doi:10.1186/s40168-019-0721-7 · Cited by 528
Short-chain fatty acids as potential regulators of skeletal muscle metabolism and function
Frampton, J. E., Murphy, K. G., Frost, G. S., & Chambers, E. S. (2020) · Nature Metabolism · doi:10.1038/s42255-020-0188-7 · Cited by 552
Polyphenol-Mediated Gut Microbiota Modulation: Toward Prebiotics and Further
Rodríguez-Daza, M.-C., Pulido-Mateos, E. C., Lupien‐Meilleur, J., Guyonnet, D., Desjardins, Y., & Roy, D. (2021) · Frontiers in Nutrition · doi:10.3389/fnut.2021.689456 · Cited by 511
Metadata
- Authors
- Grosicki, G. J., Fielding, R. A., & Lustgarten, M. S.
- Affiliations
- Tufts University (US)
- Corresponding author
- Lustgarten, Michael S.
- Venue
- Calcified Tissue International
- Published
- 2017-10-20
- Volume
- 102
- Issue
- 4
- Pages
- 433-442
- ISSN
- 0171-967X (ISSN-L)
- 1432-0827
- PMC
- PMC5858871
- OpenAlex
- W2765923427
- Cited by
- 388
- References
- 106
- Citations by year
- 2026: 39 · 2025: 52 · 2024: 67 · 2023: 44 · 2022: 46 · 2021: 44 · 2020: 52 · 2019: 31 · 2018: 12 · 2017: 1
- FWCI
- 3.22
- Type
- journal article
- Language
- en
- Open access
- green
- www.ncbi.nlm.nih.gov
- Locations
- Calcified Tissue International (publishedVersion)
- PubMed (publishedVersion)
- PubMed Central (acceptedVersion)
- Funders
- U.S. Department of Agriculture (58-1950-4-003)
- National Institute on Aging (5K01AG050700-02)
- Topics
- Health Sciences › Medicine › Physiology (medical) › Nutrition and Health in Aging
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Gut microbiota and health
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Muscle Physiology and Disorders
- Keywords
- gut microbiota, gut-muscle axis, sarcopenia, skeletal muscle aging, muscle mass, muscle composition, muscle function, dysbiosis, intestinal permeability, lipopolysaccharide, indoxyl sulfate, inflammation, muscle plasticity
- MeSH terms
- Gastrointestinal Microbiome, Age Factors, Animals, Biological Products, Humans, Muscle, Skeletal, Gastrointestinal Tract, Microbiota
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
A language model drew the claims from the paper on 2026-10-10, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).
A second model labelled each claim on 2026-10-10 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).
Cited sources are checked with a language model’s help (gpt-6-sol).
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
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