The athletic gut microbiota

In the paper

“In distance runners, protein intake was negatively correlated with diversity (Shannon index R = − 0.63; P = 0.01) and in bodybuilders, fat intake was negatively correlated with Bifidobacteria (R = − 0.52; P = 0.05).”

What the sources say

• Supported

  The Results (Microbial taxonomy, Fig. 2b) report that fat intake was negatively correlated with the relative abundance of Bifidobacterium in bodybuilders (r = −0.52, p = 0.048). The citing sentence rounds the p-value to 0.05. (LLM, conf=0.95)

  cites [11] Jang LG, 2019, J Int Soc Sports Nutr source

In the paper

“For example, of subjects undergoing dietary calorie restriction treatment for obesity, those with higher levels of these bacteria exhibited the best metabolic status and clinical outcomes [59].”

What the sources say

• Supported

  The Discussion reports that overweight and obese participants with higher A. muciniphila abundance had healthier metabolic status and better outcomes after calorie restriction. The Abstract likewise reports greater improvement in insulin-sensitivity markers and other clinical parameters among those with higher baseline abundance. (LLM, conf=0.92)

  cites [59] Dao MC, 2016, Gut. source

In the paper

“the gut microbiota produces and releases an enormous array of compounds which may act upon host tissues modulating appetite, gut motility, energy uptake and storage, and energy expenditure [146, 147].”

What the sources say

• Supported

  The Summary states that the gut microbiota produces metabolites and bacterial products that signal to host tissues, changing appetite, gut motility, energy uptake and storage, and energy expenditure. The Abstract makes the same point and gives examples of those compounds. No page numbers are provided in our copy. (LLM, conf=0.94)

  cites [146] Heiss CN, 2018, J Innate Immun source
• Partly supported

  The Menu of Molecules and Outlook sections describe a wide range of microbiota-produced compounds, some of which reach host tissues or participate in host signaling. The paper links bacterial tryptamine to enteric nervous-system signaling, but the passages do not establish the claimed effects on appetite, gut motility, energy uptake and storage, or energy expenditure. (LLM, conf=0.86)

  cites [147] Donia MS, 2015, Science. sourceExperimental — accuracy not yet measured

In the paper

“Excessive fermentation of dietary protein in the GI tract is generally considered detrimental given the production of toxic by-products such as amines, phenols, indoles, thiols, and ammonia [182, 183].”

What the sources say

• Not checked yetcites [182] Macfarlane GT, 2012, J AOAC Int source
• Partly supported

  The Introduction says excessive dietary-protein fermentation should be avoided because it produces detrimental substances. The section on the microbial ecosystem names ammonia, amines, phenols and indoles as potentially toxic products, but our copy does not identify thiols as one of them. (LLM, conf=0.88)

  cites [183] Rist VT, 2013, Animal. sourceExperimental — accuracy not yet measured

In the paper

“Prevotella is normally found in only a small percentage of healthy individuals in European and American cohorts [1, 2, 20, 210].”

What the sources say

• ?Could not verify

  The ‘Microbial diversity of healthy humans’ section identifies Prevotella in subgingival plaque and mentions gut Prevotella copri, but gives no percentage of healthy individuals carrying the genus. Searches for Prevotella prevalence and European or American cohorts found no passage establishing the claimed low prevalence. (LLM, conf=0.76)

  cites [1] Human Microbiome Project C, 2012, Nature. sourceExperimental — accuracy not yet measured
• ?Could not verify

  The Common bacterial core section (p. 3) discusses species abundance and healthy controls, but does not identify Prevotella or report how often it occurs in healthy individuals. The Discussion (p. 6) describes a European cohort and mentions American studies without giving Prevotella prevalence. Searches for Prevotella and for its prevalence in European and American cohorts found no passage addressing the claim. (LLM, conf=0.76)

  cites [2] Qin J, 2010, Nature. sourceExperimental — accuracy not yet measured
• Partly supported

  The Results (Identification of community classes in human microbiota; page unavailable) assign 7.2% of healthy HMP stool samples to a Prevotella-dominated enterotype, and identify a comparable enterotype in a European study. But an enterotype is not the same as the presence of Prevotella: the paper does not establish that the genus is found in only a small percentage of healthy people in European and American cohorts. (LLM, conf=0.88)

  cites [20] Zhou Y, 2014, Genome Biol sourceExperimental — accuracy not yet measured
• Partly supported

  The Background says Western American and European gut microbiomes tend to be dominated by Bacteroides and Clostridiales rather than Prevotella. The Results and discussion reports lower Prevotella abundance in Western samples, but does not establish that Prevotella is found in only a small percentage of healthy European and American individuals. Its figure of 75% of samples having less than 5% Prevotella refers to relative abundance across all studies, not the percentage of Western individuals in whom it is found. (LLM, conf=0.86)

  cites [210] Gorvitovskaia A, 2016, Microbiome. sourceExperimental — accuracy not yet measured

In the paper

“Amongst the exercise studies in animals there was little agreement regarding what taxa are influenced by chronic exercise.”

In the paper

“In terms of human research there are few studies that have examined the effect of energy intake and energy expenditure on the gut microbiota.”

In the paper

“little is known on the effects of energy reduced diets in athletes looking to healthfully reduce bodyweight and/or improve body composition.”

In the paper

“To date, no study in athletes has addressed RED-S in relation to the gut microbiota.”

In the paper

“In contrast to high-energy intake and obesity, even less is known about the gut microbiota in undernutrition [142].”

What the sources say

• Not checked yetcites [142] Krajmalnik-Brown R, 2012, Nutr Clin Pract source

In the paper

“Various studies have explored the gut microbiota of anorexia nervosa patients with the majority of them being characterized by heterogeneity in the methodology and small sample sizes (for review see: [167]).”

What the sources say

• Not checked yetcites [167] Mack I, 2018, Curr Neuropharmacol source

In the paper

“The variation in microbial analysis across different studies can make comparing/contrasting study findings difficult.”

In the paper

“The majority of studies in the present review did not report power and sample size calculations.”

In the paper

“The microorganisms in the gastrointestinal tract play a significant role in nutrient uptake, vitamin synthesis, energy harvest, inflammatory modulation, and host immune response, collectively contributing to human health.”

• Also stated in: § Introduction · plain

  “The microorganisms in the gastrointestinal (GI) tract play a role in nutrient uptake, vitamin synthesis, energy harvest, inflammatory modulation, and host immune response [3, 4].”

What the sources say

• Not checked yetcites [3] Cronin O, 2016, Curr Opin Gastroenterol source
• Not checked yetcites [4] Ursell LK, 2012, Nutr Rev source

In the paper

“However, the amount of exercise (time reported exercising during the average week) was correlated positively with a greater abundance of the genus Prevotella (≥2.5%).”

What the sources say

• Not checked yetcites [18] Petersen LM, 2017, Microbiome. source

In the paper

“In addition, the gut microbiota with its ability to harvest energy, modulate the immune system, and influence gastrointestinal health, likely plays an important role in athlete health, wellbeing, and sports performance.”

• Also stated in: § Introduction · hedged

  “In addition, the gut microbiota with its ability to harvest energy, modulate the immune system, and influence mucosal and brain health, is likely to play a significant role in athlete health, wellbeing, and sports performance [13–15].”

What the sources say

• Not checked yetcites [13] Barton W, 2018, Gut.
• Not checked yetcites [14] Estaki M, 2016, Microbiome. source
• Not checked yetcites [15] Clark A, 2016, J Int Soc Sports Nutr source

In the paper

“Relative to controls athletes appear to have increases in metabolic pathways (e.g., amino acid and antibiotic biosynthesis and carbohydrate metabolism) and fecal metabolites (e.g., microbial produced short-chain fatty acids (SCFAs) including acetate, propionate, and butyrate) associated with enhanced fitness and overall health when compared to control groups [13].”

What the sources say

• Not checked yetcites [13] Barton W, 2018, Gut.

In the paper

“Differences in fecal microbiota between athletes and sedentary controls showed even greater separation at the metagenomic and metabolomic level than at the gut microbiota compositional level.”

What the sources say

• Not checked yetcites [13] Barton W, 2018, Gut.

In the paper

“Furthermore, athletes have an enriched profile of SCFAs, previously associated with numerous health benefits and a lean phenotype [61–63].”

What the sources say

• Not checked yetcites [61] Hamer HM, 2009, Clin Nutr source
• Not checked yetcites [62] Koh A, 2016, Cell. source
• Not checked yetcites [63] Ridaura VK, 2013, Science. source

In the paper

“Moreover, protein consumption was correlated positively (R = 0.24–0.43) with microbial diversity across all groups, indicating that greater protein intake was linked to higher levels of microbial diversity.”

What the sources say

• Not checked yetcites [19] Clarke SF, 2014, Gut. source

In the paper

“Using metagenomic whole genome shotgun sequencing, no significant correlations were evident between the taxonomic clusters in professional or amateur cycling status.”

What the sources say

• Not checked yetcites [18] Petersen LM, 2017, Microbiome. source

In the paper

“Increased abundance of Prevotella, common in non-Western populations and associated with plant/fiber rich diets, was further positively correlated with several amino acid and carbohydrate metabolism pathways, including branched-chain amino acid (BCAA) metabolism.”

What the sources say

• Not checked yetcites [18] Petersen LM, 2017, Microbiome. source

In the paper

“In distance runners, protein intake was negatively correlated with diversity (Shannon index R = − 0.63; P = 0.01) and in bodybuilders, fat intake was negatively correlated with Bifidobacteria (R = − 0.52; P = 0.05).”

What the sources say

• Not checked yetcites [11] Jang LG, 2019, J Int Soc Sports Nutr source

In the paper

“Using metatranscriptomic sequencing, there was increased abundance of Methanobrevibacter smithii transcripts in a number of the professional cyclists in comparison to amateur cyclists.”

What the sources say

• Not checked yetcites [18] Petersen LM, 2017, Microbiome. source

In the paper

“Indeed, variation in profiling techniques (e.g., sequencing strategy, platform, variable regions, sequencing depth, etc.) may act as a confounding variable resulting in divergent findings due entirely to laboratory techniques rather than treatment [51].”

What the sources say

• Not checked yetcites [51] Bisanz JE, 2019, Cell Host Microbe source

In the paper

“Importantly, the alpha diversity of the elite athlete’s microbiota was higher than that of both control groups.”

What the sources say

• Not checked yetcites [19] Clarke SF, 2014, Gut. source

In the paper

“Further, the athletes and those in the low BMI control group had higher proportions of the genus Akkermansia than the high BMI control group.”

What the sources say

• Not checked yetcites [19] Clarke SF, 2014, Gut. source

In the paper

“Clarke et al. [19] reported the gut microbiota of professional male rugby players was more diverse than healthy, non-athlete subjects matched for body mass index (BMI), age, and gender.”

What the sources say

• Not checked yetcites [19] Clarke SF, 2014, Gut. source

In the paper

“Further, quantitative polymerase chain reaction analysis revealed higher abundance of health-promoting bacterial species in active women, including Faecalibacterium prausnitzii, Roseburia hominis and Akkermansia muciniphila.”

What the sources say

• Not checked yetcites [56] Bressa C, 2017, PLoS One source

In the paper

“These findings support of the notion that other factors beyond BMI levels should be considered when assessing any relationship between metabolic health, obesity and the microbiome status of competitive athletes.”

In the paper

“While evidence is currently limited, results from Clarke et al. [19] and Petersen et al. [18] suggest A. muciniphilia may be more present in athletes than non-athletes.”

What the sources say

• Not checked yetcites [19] Clarke SF, 2014, Gut. source
• Not checked yetcites [18] Petersen LM, 2017, Microbiome. source

In the paper

“Activation of pro-inflammatory cytokines is observed, leading to the chronic low-grade inflammation often implicated in obesity [69].”

What the sources say

• Not checked yetcites [69] Khan MJ, 2016, J Obes

In the paper

“The changes in the Firmicutes/Bacteroidetes ratio exerted by exercise were inversely proportional to the distance traveled by animals [74].”

What the sources say

• Not checked yetcites [74] Evans CC, 2014, PLoS One

In the paper

“In contrast, athletes have been noted to have lower levels of circulating LPS compared to sedentary individuals [70].”

What the sources say

• Not checked yetcites [70] Lira FS, 2010, Lipids Health Dis source

In the paper

“For example, Rugby or American football players commonly have large amounts of lean mass, and many will have relatively healthy percent body fat levels, typically 12–20%, so BMI is considered to be a poor measure of obesity status in these athletic cohorts.”

What the sources say

• Not checked yetcites [67] Maffetone PB, 2015, Sports Med Open source

In the paper

“These preliminary studies indicate that exercise influences the composition of the gut microbiota community.”

What the sources say

• Not checked yetcites [17] Cerda B, 2016, Front Physiol source
• Not checked yetcites [71] Cook MD, 2016, Immunol Cell Biol source

In the paper

“Animal and human data have reported that the Firmicutes/Bacteroidetes ratio is higher (i.e., increased Firmicutes and/or decreased Bacteroidetes) in obese people compared to lean people [79–82].”

What the sources say

• Not checked yetcites [79] Ley RE, 2006, Nature. source
• Not checked yetcites [80] Ley RE, 2005, Proc Natl Acad Sci U S A source
• Not checked yetcites [81] Kasai C, 2015, BMC Gastroenterol source
• Not checked yetcites [82] Koliada A, 2017, BMC Microbiol source

In the paper

“Other than a positive correlation between exercise and Lactobacillus [73, 86, 87], there are no other taxa that consistently increase in relative abundance in regularly exercised mice or rats.”

What the sources say

• Not checked yetcites [73] Choi JJ, 2013, Environ Health Perspect source
• Not checked yetcites [86] Petriz BA, 2014, BMC Genomics source
• Not checked yetcites [87] Queipo-Ortuno MI, 2013, PLoS One

In the paper

“Other animal studies demonstrated that daily wheel running exercise may improve some aspects of unhealthy states, such as diet-induced obesity, diabetes, and toxicity, by impacting the gut microbial composition in mice [73–75].”

What the sources say

• Not checked yetcites [73] Choi JJ, 2013, Environ Health Perspect source
• Not checked yetcites [74] Evans CC, 2014, PLoS One
• Not checked yetcites [75] Lambert JE, 2015, Appl Physiol Nutr Metab source

In the paper

“This profile along with an increased number of detected SCFA pathways in athletes is conducive to an enhanced rate of SCFA production [64].”

What the sources say

• Not checked yetcites [64] den Besten G, 2013, J Lipid Res source

In the paper

“In healthy individuals, Estaki et al. [14] reported higher cardiorespiratory fitness (as measured by peak or maximum oxygen uptake, VO2peak or VO2max) correlated with increases in both microbial diversity and fecal butyrate (see Table 2).”

What the sources say

• Not checked yetcites [14] Estaki M, 2016, Microbiome. source

In the paper

“Additionally, Veillonella was more prevalent among runners compared to non-runners.”

What the sources say

• Not checked yetcites [16] Scheiman J, 2019, Nat Med source

In the paper

“Durk et al. [93] also explored the relationship between cardiorespiratory fitness and relative gut microbiota composition in healthy young adults showing that Firmicutes/Bacteroidetes ratio was significantly positively correlated to VO2max.”

What the sources say

• Not checked yetcites [93] Durk RP, 2019, Int J Sport Nutr Exerc Metab source

In the paper

“Additionally, enhanced bacterial diversity was correlated positively with certain microbial metabolic functions including chemotaxis, motility, and fatty acid biosynthesis.”

What the sources say

• Not checked yetcites [14] Estaki M, 2016, Microbiome. source

In the paper

“Increases in fecal butyrate were observed when relative abundances of Clostridiales, Roseburia, Lachnospiraceae, and Erysipelotrichaceae were increased [14].”

What the sources say

• Not checked yetcites [14] Estaki M, 2016, Microbiome. source

In the paper

“In a cross-sectional study in premenopausal women, cardiorespiratory fitness was associated with gut microbiota composition, independent of age and carbohydrate or fat intake [94].”

What the sources say

• Not checked yetcites [94] Yang Y, 2017, Nutrients. source

In the paper

“Functional categories most strongly correlated with VO2peak were related to bacterial motility (bacterial motility proteins, flagella assembly, and bacterial chemotaxis), sporulation, and to a lesser extent the two-component system known to enable bacterial communities to sense and respond to environmental factors [14].”

What the sources say

• Not checked yetcites [14] Estaki M, 2016, Microbiome. source

In the paper

“Several other studies using murine-based models also demonstrated increased alpha diversity in animals that exercised vs. those that were sedentary [73, 74, 86, 87].”

What the sources say

• Not checked yetcites [73] Choi JJ, 2013, Environ Health Perspect source
• Not checked yetcites [74] Evans CC, 2014, PLoS One
• Not checked yetcites [86] Petriz BA, 2014, BMC Genomics source
• Not checked yetcites [87] Queipo-Ortuno MI, 2013, PLoS One

In the paper

“At the species level there was a marked increase in the families Coriobacteriaceae and Succinivibrionaceae.”

What the sources say

• Not checked yetcites [20] Zhou Y, 2014, Genome Biol source

In the paper

“In professional rugby players, who had a unique dietary pattern (higher energy intake and quantities of protein, fat, carbohydrates, sugar and saturated fat per day, with protein accounting for considerably more of the total energy) and a high level of physical activity, there was a higher diversity of gut microbiota compared with controls [19].”

What the sources say

• Not checked yetcites [19] Clarke SF, 2014, Gut. source

In the paper

“A common finding in these murine studies examining the effects of exercise training on the gut microbiome, is an increase in alpha diversity [17].”

What the sources say

• Not checked yetcites [17] Cerda B, 2016, Front Physiol source

In the paper

“These findings highlight a microbiota-derived mechanism for the health-promoting benefits of exercise.”

In the paper

“As VO2peak was not significantly associated with variation in community composition, this result suggests function may be a better predictor than species richness, as noted previously.”

In the paper

“Exercise training attenuates inflammation in part by reducing elevated blood LPS [70].”

What the sources say

• Not checked yetcites [70] Lira FS, 2010, Lipids Health Dis source

In the paper

“The primary findings indicate that cardiorespiratory fitness is a good predictor of gut microbial diversity in healthy humans, outperforming several other variables including sex, age, BMI, and multiple dietary components.”

In the paper

“Finally, it has been observed that exercise induces more effective changes in the microbiota in juvenile rats than in adult rats [90].”

What the sources say

• Not checked yetcites [90] Mika A, 2015, PLoS One source

In the paper

“For example, regular forced exercise differentially affected microbiota richness whether they were obese-hypertensive or normal rats [86].”

What the sources say

• Not checked yetcites [86] Petriz BA, 2014, BMC Genomics source

In the paper

“While no other relationships between the gut microbiota and fitness, nutritional intake, or anthropometric variables were found, VO2max accounted for ~ 22% of the variance of an individual’s relative gut bacteria (as determined by the Firmicutes/Bacteroidetes ratio).”

What the sources say

• Not checked yetcites [93] Durk RP, 2019, Int J Sport Nutr Exerc Metab source

In the paper

“Continuous low-level translocation of LPS into circulation can induce chronic low-level inflammatory states associated with development of obesity and other metabolic syndromes [92].”

What the sources say

• Not checked yetcites [92] Monteiro R, Azevedo I. Chronic inflammation in obesity and the metabolic syndrome. Mediat Inflamm. 2010;2010. https://doi.org/10.1155/2010/289645. source

In the paper

“After adjusting for age and dietary intake, all significant associations remained.”

What the sources say

• Not checked yetcites [94] Yang Y, 2017, Nutrients. source

In the paper

“At the phylum level, Lentisphaerae and Acidobacteria, whose functions in the human gut are unknown, were detected after running.”

What the sources say

• Not checked yetcites [20] Zhou Y, 2014, Genome Biol source

In the paper

“Interestingly, the pentose phosphate pathway, a metabolic pathway parallel to glycolysis and involving the oxidation of glucose, was the most enriched pathway after a half-marathon run.”

What the sources say

• Not checked yetcites [20] Zhou Y, 2014, Genome Biol source

In the paper

“Also identified was a core set of gene related functions rather than a core set of bacterial taxa in individuals with high levels of fitness [14].”

What the sources say

• Not checked yetcites [14] Estaki M, 2016, Microbiome. source

In the paper

“Given the limited prevalence of the methylmalonyl-CoA pathway across lactate-utilizing microbes, this enrichment post-exercise may implicate Veillonella in causing functional changes in the metabolic repertoire of the gut microbiota.”

In the paper

“Liu and colleagues were able to establish a model based on a machine-learning algorithm from baseline microbiome signatures which accurately predicted the exercise outcomes with respect to glycemic control and insulin sensitivity.”

What the sources say

• Not checked yetcites [106] Liu Y, 2019, Cell Metab source

In the paper

“16S rRNA gene-based metagenomic analyses revealed that the effect of endurance exercise on gut microbiota diversity was not greater than interindividual differences”

What the sources say

• Not checked yetcites [101] Taniguchi H, 2018, Phys Rep

In the paper

“Similar findings were reproduced as relative taxonomic abundances Veillonella were increased post-exercise.”

What the sources say

• Not checked yetcites [16] Scheiman J, 2019, Nat Med source

In the paper

“However, Bacteroides sometimes correlate with higher BMI and a Westernized diet [105]”

What the sources say

• Not checked yetcites [105] Abenavoli L, 2019, Nutrients. source

In the paper

“Moreover, these preclinical, proof-of-concept experiments displayed for the first time that beneficial microbes from athletes can be effectively transferred to enhance performance.”

In the paper

“Gut colonization of Veillonella may augment the Cori cycle by providing an alternative lactate-processing method whereby systemic lactate is converted into SCFAs that re-enter the circulation.”

In the paper

“Of note, the exercise induced shifts in SCFA-producing taxa (Faecalibacterium species [spp.] and Lachnospira spp.) and genetic machinery (butyrate-regulating gene, BCoAT) were more substantial in lean versus obese participants.”

What the sources say

• Not checked yetcites [98] Allen JM, 2018, Med Sci Sports Exerc source

In the paper

“In a longitudinal research design, Allen et al. [98] reported for the first time that exercise training can modulate the composition and metabolic capacity of the human gut microbiota in previously sedentary individuals.”

What the sources say

• Not checked yetcites [98] Allen JM, 2018, Med Sci Sports Exerc source

In the paper

“Conversely the microbial profiles of non-responders after the exercise intervention shared more similarity with those of the sedentary controls, suggesting a maladaptation of gut microbiota in these individuals.”

What the sources say

• Not checked yetcites [106] Liu Y, 2019, Cell Metab source

In the paper

“In addition, the Veillonella methylmalonyl-CoA pathway was overrepresented in the metagenomic samples post-exercise across the cohort.”

What the sources say

• Not checked yetcites [16] Scheiman J, 2019, Nat Med source

In the paper

“The changes in these taxa were correlated with the changes in several cardiometabolic risk factors.”

What the sources say

• Not checked yetcites [101] Taniguchi H, 2018, Phys Rep

In the paper

“These findings indicate that the changes in gut microbiota were associated with cardiometabolic risk factors, such as systolic and diastolic blood pressure.”

What the sources say

• Not checked yetcites [101] Taniguchi H, 2018, Phys Rep

In the paper

“Importantly, Scheiman et al. [16] found systemic lactate in these animals was able to cross the gut barrier into the lumen, making it available as a substrate for microbial SCFA conversion.”

What the sources say

• Not checked yetcites [16] Scheiman J, 2019, Nat Med source

In the paper

“the rise of BCAA has been associated with insulin resistance [107]”

What the sources say

• Not checked yetcites [107] Newgard CB, 2009, Cell Metab source

In the paper

“the increases in Bacteroides following the exercise intervention were positively associated with increases in a 6-min walk test”

What the sources say

• Not checked yetcites [103] Morita E, 2019, Nutrients. source

In the paper

“They also more effectively converted lactate to the SCFAs propionate.”

What the sources say

• Not checked yetcites [16] Scheiman J, 2019, Nat Med source

In the paper

“Despite the overall metabolic benefits of the intervention, ~ 30% of subjects responded poorly to exercise in terms of improvement in glycemic control and insulin sensitivity.”

What the sources say

• Not checked yetcites [106] Liu Y, 2019, Cell Metab source

In the paper

“Together, the results from both the human and animal studies indicate that exercise may impose a differential impact on the composition and function of the gut microbiota across individuals.”

What the sources say

• Not checked yetcites [106] Liu Y, 2019, Cell Metab source

In the paper

“Veillonella species metabolize lactate into the SCFA acetate and propionate via the methylmalonyl-CoA pathway [97].”

What the sources say

• Not checked yetcites [97] Ng SK, 1973, Can J Microbiol source

In the paper

“While other studies reported butyrate as a prominent feature of the athletic microbiota [13, 14, 72, 88, 98, 99], this research implicated propionate as another significant beneficial SCFA.”

In the paper

“responders displayed greater gene expression of functional pathways generating SCFAs and breaking down BCAAs.”

What the sources say

• Not checked yetcites [106] Liu Y, 2019, Cell Metab source

In the paper

“changes in alpha diversity indices during intervention were negatively correlated with changes in systolic and diastolic blood pressure, especially during exercise”

What the sources say

• Not checked yetcites [101] Taniguchi H, 2018, Phys Rep

In the paper

“After the washout period, exercise-induced changes in the microbiota were largely reversed once exercise training ceased.”

What the sources say

• Not checked yetcites [98] Allen JM, 2018, Med Sci Sports Exerc source

In the paper

“intrinsic adaptations to endurance training, such as decreased blood flow, tissue hypoxia, and increased transit and absorptive capacity can lead to changes in the GI tract [114, 115].”

What the sources say

• Not checked yetcites [114] Gisolfi CV, 2000, News Physiol Sci
• Not checked yetcites [115] Rosa EF, 2005, J Appl Physiol source

In the paper

“Microbial-derived lysine may also contribute to the body protein pool in humans [113].”

What the sources say

• Not checked yetcites [113] Metges CC, 2000, J Nutr source

In the paper

“Intense exercise redistributes blood from the splanchnic circulation to actively respiring tissues [126].”

What the sources say

• Not checked yetcites [126] Qamar MI, 1987, Gut. source

In the paper

“Variations in taxonomic composition included increased abundance of butyrate producing species and species associated with improved metabolic health and improved insulin sensitivity.”

What the sources say

• Not checked yetcites [99] Keohane DM, 2019, J Sci Med Sport source

In the paper

“which play an important role in reducing muscular fatigue and damage during strenuous exercise [112].”

What the sources say

• Not checked yetcites [112] Ohtani M, 2006, J Nutr source

In the paper

“There was also a decrease in Clostridium and Blautia genera.”

What the sources say

• Not checked yetcites [109] Motiani KK, 2019, Med Sci Sports Exerc source

In the paper

“Repeated bouts of aerobic exercise can increase GI transit time in healthy individuals and middle-aged patients with chronic constipation [118–120].”

What the sources say

• Not checked yetcites [118] Strid H, 2011, Scand J Gastroenterol source
• Not checked yetcites [119] De Schryver AM, 2005, Scand J Gastroenterol source
• Not checked yetcites [120] Oettle GJ, 1991, Gut. source

In the paper

“the gene expression of functional metabolic pathways involved in L-isoleucine and L-lysine production increased”

What the sources say

• Not checked yetcites [99] Keohane DM, 2019, J Sci Med Sport source

In the paper

“This adverse effect is particularly the case in endurance sports [128].”

What the sources say

• Not checked yetcites [128] Oktedalen O, 1992, Scand J Gastroenterol source

In the paper

“the vigorous exercise group experienced a greater increase in alpha diversity at 3 months compared to control.”

What the sources say

• Not checked yetcites [108] Kern T, 2019, Int J Obes source

In the paper

“More intense exercise may be needed to induce change in the gut microbiota in sedentary, overweight/obese subjects.”

What the sources say

• Not checked yetcites [108] Kern T, 2019, Int J Obes source

In the paper

“These events render the gut mucosa susceptible to endotoxin translocation [130].”

What the sources say

• Not checked yetcites [130] Brock-Utne JG, 1988, S Afr Med J

In the paper

“Overall, the mechanisms by which physical activity may promote a rich bacterial community and increased functional pathways have not been fully elucidated but likely involve a combination of intrinsic and extrinsic factors.”

In the paper

“the increase in Bacteroidetes plays an essential role in the metabolic conversions of complex sugar polymers and degradation of proteins [110].”

What the sources say

• Not checked yetcites [110] Rajilic-Stojanovic M, 2014, FEMS Microbiol Rev source

In the paper

“both high intensity interval and moderate continuous training affected the gut microbiota in insulin resistant, sedentary individuals following a 2-week exercise intervention [109].”

What the sources say

• Not checked yetcites [109] Motiani KK, 2019, Med Sci Sports Exerc source

In the paper

“Alpha diversity increased throughout the ultra-endurance event and was evident as early as day 17 in the race.”

What the sources say

• Not checked yetcites [99] Keohane DM, 2019, J Sci Med Sport source

In the paper

“The functional potential of bacterial species involved in specific amino and fatty acid biosynthesis also increased.”

What the sources say

• Not checked yetcites [99] Keohane DM, 2019, J Sci Med Sport source

In the paper

“A single acute bout of prolonged excessive exercise can have a deleterious influence on intestinal function.”

In the paper

“lower abundance of Blautia genus was associated with better whole-body insulin sensitivity.”

What the sources say

• Not checked yetcites [109] Motiani KK, 2019, Med Sci Sports Exerc source

In the paper

“at higher intensities (e.g., above 70% VO2max), gastric emptying appears to be delayed [121–124].”

What the sources say

• Not checked yetcites [121] Horner KM, 2015, Sports Med source
• Not checked yetcites [122] Rehrer NJ, 1989, Med Sci Sports Exerc source
• Not checked yetcites [123] Neufer PD, 1989, Eur J Appl Physiol Occup Physiol source
• Not checked yetcites [124] Feldman M, 1982, J Appl Physiol Respir Environ Exerc Physiol