CoChat
Sign Up
Cited by 641Gut microbiota and healthNutritional Studies and DietAtherosclerosis and Cardiovascular Diseases

The contributory role of gut microbiota in cardiovascular disease

Open access
Tang, W.H. Wilson, Hazen, Stanley L.·2014·Journal of Clinical Investigation
DOI 10.1172/jci72331PMC PMC4215189
Open this paper in CoChat — free accountOpen PDF

Abstract

Our group recently discovered that certain dietary nutrients possessing a trimethylamine (TMA) moiety, namely choline/phosphatidylcholine and L-carnitine, participate in the development of atherosclerotic heart disease. A meta-organismal pathway was elucidated involving gut microbiota-dependent formation of TMA and host hepatic flavin monooxygenase 3-dependent (FMO3-dependent) formation of TMA-N-oxide (TMAO), a metabolite shown to be both mechanistically linked to atherosclerosis and whose levels are strongly linked to cardiovascular disease (CVD) risks. Collectively, these studies reveal that nutrient precursors, gut microbiota, and host participants along the meta-organismal pathway elucidated may serve as new targets for the prevention and treatment of CVD.

AI snapshot

Written from the paper’s full text.

TL;DR

This review proposes that gut microbes convert dietary choline/phosphatidylcholine and L-carnitine into trimethylamine (TMA), which the liver enzyme FMO3 oxidizes to trimethylamine-N-oxide (TMAO), a metabolite linked to atherosclerosis and cardiovascular events. It presents this diet–microbe–host pathway as a possible target for preventing or treating cardiovascular disease.

Key findings

  • In a validation cohort of 1,876 subjects, plasma choline, betaine, and TMAO were associated with cardiovascular risk, with TMAO showing the strongest correlation. In more than 4,000 patients undergoing elective coronary angiography, those in the highest TMAO quartile had a 2.5-fold higher risk of myocardial infarction, stroke, or death over 3 years, independent of traditional risk factors, renal function, and medication use.
  • Animal and human studies indicate an obligatory role for gut microbiota in TMA/TMAO formation from dietary precursors: germ-free mice and antibiotic/isotope-labeling studies support this, egg yolk or labeled phosphatidylcholine raises TMAO, and L-carnitine promotes atherosclerosis only when gut microbiota are intact. TMAO supplementation in apolipoprotein E-null mice increased macrophage foam cell formation and aortic root plaque, and altered reverse cholesterol transport and bile acid pools.
  • Chronic diet shapes microbial TMA-producing capacity: vegetarians and vegans had lower TMA/TMAO production from L-carnitine than omnivores, and chronic L-carnitine exposure increased TMA synthetic capacity 10-fold in mice. Microbial choline TMA lyase (cutC/D) and carnitine TMA lyase (CntA/B) generate TMA, while hepatic FMO3 converts TMA to TMAO, with FMO3 activity at least 10-fold higher than FMO1 or FMO2.
  • TMAO was also associated with adverse prognosis in heart failure patients (n = 720) and predicted incident chronic kidney disease in Framingham data; in mice on a high-fat diet, TMAO worsened glucose tolerance, hepatic insulin signaling, and adipose inflammation. Genetic contributions appeared limited: TMAO explained 11% of atherosclerosis variation across inbred mouse strains, and human GWAS loci for TMAO did not replicate.

Methods

  • Narrative review synthesizing prior metabolomic, case-control, prospective cohort, animal-model, and in vitro studies; no new primary data are reported.
  • Key human datasets described include an initial learning cohort, independent validation cohorts, and a third validation cohort of 1,876 subjects; an angiography cohort of over 4,000; a carnitine cohort of 2,595; a heart failure cohort of 720; and a human TMAO GWAS of 1,973 subjects with 1,892 replication subjects.
  • Main analysis is interpretive synthesis of associations and mechanisms linking diet, gut microbial enzymes, host FMO3, TMAO, and cardiovascular phenotypes.

Limitations

  • The paper states that direct molecular targets or receptors for TMAO have not been identified, the relative quantitative contributions of cutC/D versus CntA/B in humans are unknown, and additional microbial TMA-producing enzymes likely remain undiscovered.
  • The paper notes that human genetic signals for TMAO were weak and failed replication, that the rarity of FMO3 deficiency (trimethylaminuria) has prevented assessment of a cardiovascular phenotype, and that nutritional epidemiology is confounded by mixed dietary factors with potentially opposing effects.
  • Evident from the text: as a narrative review, it does not systematically assess study quality or bias, and the author discloses patents, consultancies, research funding, and royalty interests related to cardiovascular diagnostics and therapeutics, which may bear on interpretation.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1172/jci72331

Cites

24 of 24 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 121 cited sources checked · 0 supported · 0 flagged

  • Premisecitation

    A meta-organismal pathway was elucidated in which gut microbiota form TMA and host hepatic FMO3 forms TMAO.

    “A meta-organismal pathway was elucidated involving gut microbiota-dependent formation of TMA and host hepatic flavin monooxygenase 3dependent (FMO3-dependent) formation of TMA-N-oxide (TMAO), a metabolite shown to be both mechanistically linked to atherosclerosis and whose levels are strongly linked to cardiovascular disease (CVD) risks.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [25] source

      Not checked in the free run.

  • Premisecitation

    TMAO is mechanistically linked to atherosclerosis.

    “a metabolite shown to be both mechanistically linked to atherosclerosis and whose levels are strongly linked to cardiovascular disease (CVD) risks.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [25] source

      Not checked in the free run.

    • cites [39] source

      Not checked in the free run.

  • Premiseown data

    Dietary nutrients containing a trimethylamine moiety, specifically choline/phosphatidylcholine and L-carnitine, participate in the development of atherosclerotic heart disease.

    “Our group recently discovered that certain dietary nutrients possessing a trimethylamine (TMA) moiety, namely choline/ phosphatidylcholine and L-carnitine, participate in the development of atherosclerotic heart disease.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [25] source

      Not checked in the free run.

    • cites [39] source

      Not checked in the free run.

  • Premisecitation

    Even with high-potency statin therapy, at least half of residual cardiovascular risk remains.

    “Indeed, even with high-potency statin therapy, at least a 50% residual risk remains (6), with the majority of events unchecked.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [6] source

      Not checked in the free run.

  • Premisecitation

    Large-scale GWAS have accounted for less than one-fifth of the cardiovascular risk attributable to genetic determinants.

    “Despite extensive investigations in search of causal genetic variants, such as large-scale GWAS, less than one-fifth of attributable cardiovascular risk has been accounted for from genetic determinants (3,4).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [3] source

      Not checked in the free run.

    • cites [4] source

      Not checked in the free run.

  • Classified as probably not a substantial claim. 16
  • May combine two claims. 36

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Firmicutes and Bacteroidetes are the major bacterial phyla in gut microbiota, and their proportions appear stable over time within individuals and family members.

    “The major taxa present in gut microbiota consist primarily of 2 major bacterial phyla, Firmicutes and Bacteroidetes, whose proportions appear to remain remarkably stable over time within individuals and their family members (9, 10).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [9] source

      Not checked in the free run.

    • cites [10] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The human gut contains more than 100 trillion microbial cells, far exceeding the number of human host cells.

    “We now know that the human gut harbors more than 100 trillion microbial cells, far outnumbering the human host cells of the body (8).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [8] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The remaining gut microbiota composition is diverse and dynamic, and acute and chronic dietary exposures significantly affect the overall microbial community.

    “However, the composition of the remaining gut microbiota is remarkably diverse and dynamic, with both acute and chronic dietary exposures significantly affecting the overall microbial community (8,11).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [8] source

      Not checked in the free run.

    • cites [11] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    TMAO supplementation in apolipoprotein E-null mice enhanced macrophage foam cell formation in the artery wall and peritoneal cavity and promoted aortic root atherosclerotic plaque development.

    “TMAO supplementation of apolipoprotein E-null mice was observed to foster enhanced macrophage foam cell formation in both the artery wall and the peritoneal cavity, as well as to promote aortic root atherosclerotic plaque development (25).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [25] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Elevated circulating carnitine, choline, or betaine levels are each associated with future MI, stroke, or death independent of traditional risk factors, but their prognostic value is primarily restricted to those with elevated TMAO.

    “Thus, while elevated circulating carnitine, choline, or betaine levels (all substrates of gut microbiota and dietary precursors of TMA/TMAO production) were each associated with future risk of MI, stroke, or death independent of traditional risk factors, their prognostic values were primarily restricted to those with concomitantly elevated TMAO levels (39,55).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [39] source

      Not checked in the free run.

    • cites [55] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    The gut microbial ecosystem can be considered the largest endocrine organ in the body, producing biologically active compounds that circulate and affect distant host sites.

    “The gut microbial ecosystem is arguably the largest endocrine organ in the body, capable of producing a wide range of biologically active compounds that, like hormones, may be carried in the circulation and distributed to distant sites within the host, thereby influencing different essential biological processes.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Patients in the upper quartile for TMAO had a 2.5-fold increased risk of major adverse cardiac events compared with the lowest quartile, independent of traditional risk factors, renal function, and medication use, and had poorer event-free survival.

    “Specifically, patients in the upper quartile for TMAO levels (compared with the lowest quartile) had a significant, 2.5-fold increased risk of experiencing a major adverse cardiac event (MI, stroke, or death), independent of traditional cardiovascular risk factors, renal function, and medication use, as well as overall poorer event-free survival (37).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [37] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    TMAO enters the circulation and is predominantly excreted by the kidneys.

    “TMAO enters the circulation, where it is predominantly excreted by the kidneys.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [53] source

      Not checked in the free run.

    • cites [57] Bell, 1991, Biochim Biophys Acta. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    TMAO affects cholesterol and sterol metabolism in animal models, enhancing macrophage cholesterol accumulation and atherosclerosis development.

    “TMAO has been shown to affect cholesterol and sterol metabolism in animal models, enhancing macrophage cholesterol accumulation and atherosclerosis development.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [25] source

      Not checked in the free run.

    • cites [39] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    TMAO levels explain a significant portion of atherosclerosis aortic root development across multiple inbred mouse strains, and TMAO levels are influenced by hepatic Fmo3, which is regulated in part by FXR.

    “Further investigations revealed that TMAO levels help to explain a significant portion of atherosclerosis aortic root development across multiple different inbred strains of mice, and that TMAO levels are influenced by hepatic Fmo3, which is under complex control, including regulation by the farnesoid X receptor (FXR), a bile acid-activated nuclear receptor (54).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [54] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Gut microbiota play important metabolic roles across a wide range of disease states, maintaining balances and cross-talk within the host and among microbes.

    “It is now increasingly clear that gut microbiota play important metabolic roles in a far wider range of disease states, maintaining delicate balances and cross-talk within the human host and among themselves (12).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [12] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    Other dietary nutrients with a TMA moiety, such as glycerophosphocholine, betaine, acyl carnitines, and sphingomyelin, likely have additional gut microbe-dependent pathways to TMA and TMAO, though these are largely unexplored.

    “Since other dietary nutrients possess a TMA moiety (e.g., glycerophosphocholine, betaine, various short-and long-chain acyl carnitines, and sphingomyelin), there are likely other gut microbe-dependent pathways that lead to the formation of TMA and TMAO, though these remain largely unexplored.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    The studies reveal new potential treatment targets to reduce cardiovascular risk: dietary changes, gut microbial composition and enzyme pathways, and host enzymes such as hepatic FMO3.

    “The studies described above thus reveal new potential dietary changes, gut microbial composition and enzyme pathways, and host enzymes (e.g., hepatic FMO3) as potential treatment targets to reduce cardiovascular risk (Figure 3).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    In mice fed a high-fat diet, dietary TMAO may exacerbate impaired glucose tolerance, obstruct hepatic insulin signaling, and promote adipose tissue inflammation.

    “Furthermore, results from recent studies in mice fed a high-fat diet also suggest that dietary TMAO may exacerbate impaired glucose tolerance, obstruct hepatic insulin signaling, and promote adipose tissue inflammation (59).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [59] Gao, 2014, J Biosci Bioeng.

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Chronic dietary exposure shifts gut microbial composition, giving a selective advantage to bacterial species that prefer L-carnitine as a carbon fuel source, increasing their proportion and TMA production potential.

    “Thus, chronic dietary exposure (e.g., omnivore vs. vegan/vegetarian among humans, or normal chow vs. chow plus L-carnitine in mouse studies) shifts gut microbial composition, with a selective advantage for bacterial species that prefer L-carnitine as a carbon fuel source to increase in proportion within the community and amplify the potential to produce TMA.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [39] source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    Inhibition of microbial choline and/or carnitine TMA lyases may be a potential therapeutic target for CVD by reducing microbial TMA and host TMAO formation.

    “In theory, inhibition of microbial choline and/or carnitine TMA lyases may serve as a potential therapeutic target for CVD through the reduction of microbial TMA and subsequent host TMAO formation.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Numerous large-scale epidemiologic studies link red meat ingestion with heightened mortality and CVD risks, while the relationship between egg ingestion and cardiovascular risks shows conflicting results.

    “While numerous large-scale epidemiologic studies have linked red meat ingestion with heightened mortality and CVD risks, the relationship between egg ingestion and cardiovascular risks has shown conflicting results (40-49).”
    Quote in the paperNot a substantial claim0 of 10 sources checked
    • cites [40] source

      Not checked in the free run.

    • cites [41] source

      Not checked in the free run.

    • cites [42] source

      Not checked in the free run.

    • cites [43] source

      Not checked in the free run.

    • cites [44] source

      Not checked in the free run.

    • cites [45] Djousse, 2008, Am J Clin Nutr. source

      Not checked in the free run.

    • cites [46] source

      Not checked in the free run.

    • cites [47] Qureshi, 2007, Med Sci Monit.

      Not checked in the free run.

    • cites [48] source

      Not checked in the free run.

    • cites [49] Tran, 2014, Diabetes Metab Syndr Obes. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Chronic dietary exposure can profoundly affect TMA synthetic capacity, whereas single acute dietary exposures affect TMA and TMAO production mainly by modulating precursor substrate availability.

    “Chronic dietary exposure can produce a profound effect on TMA synthetic capacity, whereas single (acute) dietary exposures affect TMA and TMAO production predominantly via modulation of precursor substrate availability.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [39] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Recombinant isolated CntA/B formed a two-component Rieske-type oxygenase/reductase complex.

    “Characterization of recombinant isolated CntA/B showed they formed a 2-component Rieske-type oxygenase/reductase complex (77).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [77] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    A different report found only a weak link between choline and betaine intake and cardiovascular disease, and it became non-significant after adjustment for cardiovascular risk markers.

    “However, an alternative report noted only a modest association with choline and betaine intake and CVD (68), which lost significance following adjustments for CVD risk markers (67,69).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [68] source

      Not checked in the free run.

    • cites [67] Rajaie, 2011, ARYA Atheroscler.

      Not checked in the free run.

    • cites [69] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Vegetarians and vegans have a much lower capacity to form TMA and TMAO from dietary L-carnitine and have lower plasma TMAO than omnivores.

    “We previously showed that vegetarians and vegans have markedly reduced synthetic capacity to make TMA and TMAO from dietary L-carnitine and have lower plasma TMAO levels than omnivores (39).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [39] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    Nutritional studies are confounded because they assess a wide mixture of dietary factors that can have opposing effects.

    “Nevertheless, any nutritional study has a confounding factor of evaluating a broad mix of nutritional factors that may have opposing effects.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Choline occurs in most animal foods and some plant foods, with especially high amounts in egg yolk, meats, liver, fish, high-fat dairy, and certain nuts.

    “Choline is present in most animal and some plant products, but is particularly abundant in egg yolk, meats, liver, fish, high-fat dairy products, and some nuts (34).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [34]

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In animal models of renal dysfunction, the oral charcoal absorbent AST-120 decreased necrotic areas and lessened aortic deposition of indoxyl sulfate without affecting lesional macrophage or collagen content, while attenuating monocyte inflammation.

    “in animal models of renal dysfunction, the oral charcoal absorbent AST-120 significantly decreased necrotic areas and lessened aortic deposition of the uremic toxin indoxyl sulfate without affecting lesional macrophage or collagen content (73) while attenuating monocyte inflammation (74).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [73] source

      Not checked in the free run.

    • cites [74] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The cut gene cluster contains catalytic cutC and regulatory cutD, both required for anaerobic TMA production from choline.

    “The microbial enzyme was found within a “choline utilization” (cut) gene cluster that contains several tightly clustered genes, including a catalytic unit (cutC) and a regulatory polypeptide (cutD), both of which were required for anaerobic TMA production from choline (75,76).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [75] source

      Not checked in the free run.

    • cites [76] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Egg whites contain many immunomodulatory and antioxidant proteins and are often eaten together with yolks when eggs are consumed.

    “Egg whites, for example, are large sources of immunmodulatory and antioxidant proteins (70), which are often ingested together with egg yolks if eggs are consumed.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [70] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    L-carnitine is a TMA precursor that the diet does not need to supply, because mammals make it from dietary lysine, the most plentiful amino acid in plant and animal proteins.

    “L-carnitine is a TMA nutrient that, in contrast to choline, is not required in our diets, since it is endogenously produced in mammals from dietary lysine, the single most abundant amino acid in plant and animal proteins (30,63,64).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [30] source

      Not checked in the free run.

    • cites [63] source

      Not checked in the free run.

    • cites [64] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    TMA has long been recognized as an odorous byproduct of choline, phosphatidylcholine, and L-carnitine decomposition, often by enterobacteria.

    “TMA has long been recognized as an odorous byproduct of choline, PC, and L-carnitine during the decomposition of plants and animals, often by enterobacteria (31).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [31] source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    Drug inhibition of FMOs, especially FMO3, is expected to lower TMAO production and might be a therapy to reduce cardiovascular risk.

    “Pharmacologic inhibition of the FMOs in general and FMO3 specifically is expected to reduce TMAO production and potentially serve as a therapy for CVD risk reduction.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: TMAO is a causal mediator of human cardiovascular disease, not merely a marker of it.

  • May combine two claims.

    Premisecitation

    A human GWAS of plasma TMAO in 1,973 people found two loci with suggestive association (P < 0.001) on chromosomes 1q23.3 and 2p12, but genotyping lead variants in 1,892 more people did not replicate the association.

    “Furthermore, GWASs for plasma TMAO levels in 1,973 humans identified 2 loci with suggestive evidence of association (P < 0.001) on chromosomes 1q23.3 and 2p12; however, genotyping of the lead variants at these loci in 1,892 additional subjects failed to replicate their association with plasma TMAO levels (60).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [60] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The microbiota converts dietary L-carnitine and choline into TMA and TMAO, which affects cholesterol and sterol metabolism in macrophages, liver, and intestine.

    “The microbiota metabolizes dietary L-carnitine and choline to form TMA and TMAO, influencing cholesterol and sterol metabolism in macrophages, liver, and intestine (39).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [39] source

      Not checked in the free run.

  • May combine two claims.

    Premisereasoning

    TMA moves through the portal circulation to hepatic FMOs, especially FMO3, which oxidize it to TMAO; TMAO then enters the circulation and is mostly excreted by the kidneys.

    “Transport via the portal circulation brings the TMA to a cluster of hepatic enzymes, the FMOs (particularly FMO3), that efficiently oxidize TMA, thus forming TMAO.TMAO enters the circulation, where it is predominantly excreted by the kidneys.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    The zinc transporter Slc30a7 may be a positional candidate for the mouse association signal, but the GWAS associations are weak.

    “Although this zinc transporter might represent a positional candidate gene responsible for the association signal at this locus in mice (60), these are weak associations in GWASs.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [60] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    FMO1, FMO2, and FMO3 can each produce TMAO, but FMO3 has at least tenfold higher specific activity than the others.

    “FMO1, FMO2, and FMO3 were all capable of forming TMAO, though the specific activity of FMO3 was at least 10-fold higher than that the other FMOs (54).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [54] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In humans and mice, hepatic FMO3 expression is lower in males than females and can be induced by dietary bile acids through an FXR-dependent pathway.

    “In both humans and mice, hepatic FMO3 expression was observed to be reduced in males compared with females (25,54) and could be induced by dietary bile acids through a mechanism that involves FXR (54).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [25] source

      Not checked in the free run.

    • cites [54] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Interpretationreasoning

    Gut microbial communities form a large and flexible endocrine organ that may affect many metabolic and physiological processes.

    “We need to appreciate that our gut microbial communities make up a large and plastic endocrine organ that may influence multiple metabolic and physiological processes.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisereasoning

    After ingestion, gut microbes can use these nutrients as a carbon source and possess TMA lyases that cleave their C-N bond to release TMA.

    “Following ingestion, gut microbiota can use these nutrients as a carbon fuel source.While mammals do not have the enzyme, gut microbes have TMA lyases, which can cleave the C-N bond of these nutrients, releasing the TMA moiety as a waste product.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Microbe-derived TMA travels quickly through the portal circulation to the liver, where hepatic FMOs efficiently oxidize it to TMAO.

    “Gut microbe-produced TMA reaches the liver rapidly via the portal circulation, where a cluster of hepatic FMO enzymes efficiently oxidizes TMA into TMAO (54,82).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [54] source

      Not checked in the free run.

    • cites [82] source

      Not checked in the free run.

  • May combine two claims.

    Premisenone given

    Multiple human studies have found that higher TMAO is independently associated with existing CVD and with incident myocardial infarction, stroke, death, and revascularization.

    “In multiple human studies, elevated TMAO has been independently associated with prevalent CVD and incident risks for MI, stroke, death, and revascularization.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    Gut microbiota are a new target for therapeutic manipulation to treat and prevent complex cardiometabolic diseases.

    “Gut microbiota represent a new target for therapeutic manipulation and targeting for the treatment and prevention of complex cardiometabolic diseases.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: TMAO is a causal mediator of human cardiovascular disease, not merely a marker of it.

  • Classified as probably not a substantial claim.

    Premisenone given

    Foods high in cholesterol and fat are often also high in phosphatidylcholine, choline, and carnitine.

    “Foods rich in cholesterol and fats are also often rich in the indicated dietary nutrients PC (lecithin), choline, and carnitine.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    FMO3 and TMAO were significantly correlated, and TMAO explained 11% of the variation in atherosclerosis among the inbred mouse strains studied.

    “FMO3 and TMAO were significantly correlated, and TMAO levels accounted for 11% of the variation in atherosclerosis across the inbred strains of mice examined (60).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [60] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Increasing FMO3 in mice raised plasma TMAO, while reducing FMO3 lowered TMAO.

    “Further, FMO3 overexpression in mice significantly increased plasma TMAO levels, while silencing FMO3 decreased TMAO levels (54).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [54] source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Interpretationnone given

    The microbial enzymes that cleave TMA from choline, phosphatidylcholine, carnitine, and other TMA-containing compounds have not yet been established.

    “bial enzyme strategies for cleaving and liberating TMA from dietary nutrients like choline, PC, and carnitine (as well as other TMAcontaining species) remains to be established.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Interpretationnone given

    Gut microbiota act as a filter for what we eat, and each person's microbial community strongly affects how a meal is experienced.

    “Gut microbiota serve as a filter for our largest environmental exposure -what we eat -and the microbial community within each of us significantly influences how we experience a meal.”
    Quote in the paperNot a substantial claim
45 of 45

  • The paper relies on this without support.

    Gut microbial community composition is influenced by host genetic variants.

    “The composition of our gut microbial community is affected not only by dietary exposures, but also by genetic variants within the hostchanges in the “terrarium” in”

  • The paper relies on this without support.

    Bile contains a high total choline/phosphatidylcholine content, and rapid turnover and sloughing of intestinal epithelial cells exposes distal gut microbes to choline independent of dietary intake.

    “Further, bile has a very high total choline (PC) content, and the rapid turnover and sloughing of intestinal epithelial cells results in significant exposure of distal gut segments (and hence microbes) to choline, independent of dietary intake.”

  • The paper relies on this without support.

    Choline and L-carnitine are found at highest levels in cholesterol- and fat-rich foods such as red meat, liver, and egg yolk.

    “It is thus remarkable that the highest levels of choline and L-carnitine are often found in foods rich in cholesterol and fats, such as red meat, liver, and egg yolk.”

  • The paper relies on this without support.

    TMAO is a causal mediator of human cardiovascular disease, not merely a marker of it.

    “Given that TMAO, and not TMA, appears to be the culprit metabolite that fosters a proatherogenic effect, one might expect that subjects with this genetic disorder are protected from CVD.”
4 of 4

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?

Cites

Flagged first, then by citations

Research works printed but not linked: 60

  1. 10.1161/01.cir.0000441139.02102.80 · DOI
  2. 10.1016/S0140-6736(10)61267-6 · DOI · Paper page
  3. 10.1093/jnci/djr189 · DOI
  4. 10.1038/nature11550 · DOI · Paper page
  5. 10.1038/nature11234 · DOI · Paper page
  6. 10.1126/science.1237439 · DOI · Paper page
  7. 10.1038/nature11552 · DOI · Paper page
  8. 10.2337/db06-1491 · DOI · Paper page
  9. 10.1159/000098542 · DOI
  10. 10.1053/j.ajkd.2009.04.022 · DOI
  11. 10.1038/nri3535 · DOI · Paper page
  12. 10.1038/nrgastro.2014.40 · DOI · Paper page
  13. 10.1053/j.gastro.2013.11.001 · DOI
  14. 10.1126/science.1241214 · DOI · Paper page
  15. Turnbaugh, 2009, J Physiol., 587, 4153, 10.1113/jphysiol.2009.174136 · DOI · Paper page
  16. 10.1038/nature07540 · DOI · Paper page
  17. 10.1038/nature05414 · DOI · Paper page
  18. 10.1038/nature09922 · DOI · Paper page
  19. Ueland, 2005, Clin Chem Lab Med., 43, 1069, 10.1515/CCLM.2005.187 · DOI
  20. 10.1016/j.clinbiochem.2010.03.009 · DOI
  21. 10.1016/S0278-6915(99)00028-9 · DOI · Paper page
  22. 10.2174/1389200054021807 · DOI · Paper page
  23. 10.1194/jlr.R700019-JLR200 · DOI
  24. Geiger, 2013, Biochim Biophys Acta., 1831, 503, 10.1016/j.bbalip.2012.08.009 · DOI
  25. 10.1007/s10545-010-9088-4 · DOI
  26. Zeisel, 2004, J Am Coll Nutr., 23, 621S, 10.1080/07315724.2004.10719433 · DOI
  27. 10.1038/nm.3145 · DOI · Paper page
  28. 10.1001/archinternmed.2011.2287 · DOI · Paper page
  29. 10.1016/j.atherosclerosis.2012.07.032 · DOI · Paper page
  30. 10.1093/aje/kwt261 · DOI · Paper page
  31. Djousse, 2008, Am J Clin Nutr., 87, 964, 10.1093/ajcn/87.4.964 · DOI · Paper page
  32. 10.1161/CIRCULATIONAHA.107.734210 · DOI · Paper page
  33. Qureshi, 2007, Med Sci Monit., 13, CR1
  34. Tran, 2014, Diabetes Metab Syndr Obes., 7, 121, 10.2147/DMSO.S58668 · DOI · Paper page
  35. 10.1073/pnas.1317834111 · DOI · Paper page
  36. 10.1007/BF00004115 · DOI
  37. 10.1073/pnas.0308633101 · DOI
  38. 10.1080/15287399409531853 · DOI · Paper page
  39. 10.1093/eurheartj/ehu002 · DOI · Paper page
  40. Tang, 2013, J Am Coll Cardiol., 61(10_S)
  41. 10.1681/ASN.2012101006 · DOI · Paper page
  42. Gao, 2014, J Biosci Bioeng., S1389-1723(14)00081-4.
  43. 10.3945/jn.110.130369 · DOI
  44. West, 2014, J Acad Nutr Diet., S2212-2672(14)00190-7
  45. 10.2174/138920006778520561 · DOI · Paper page
  46. 10.1016/j.trsl.2012.10.006 · DOI
  47. Detopoulou, 2008, Am J Clin Nutr., 87, 424, 10.1093/ajcn/87.2.424 · DOI · Paper page
  48. Rajaie, 2011, ARYA Atheroscler., 7, 78
  49. 10.1186/1471-2261-7-20 · DOI · Paper page
  50. 10.1038/sj.ejcn.1602725 · DOI · Paper page
  51. 10.1371/journal.pone.0083687 · DOI
  52. 10.1093/ndt/gfq759 · DOI · Paper page
  53. 10.1073/pnas.1215689109 · DOI · Paper page
  54. 10.1146/annurev.pharmtox.46.120604.141043 · DOI
  55. 10.1016/j.abb.2013.12.005 · DOI
  56. 10.1517/17425250802522188 · DOI
  57. Zhang, 2006, Drug Metab Dispos., 34, 19, 10.1124/dmd.105.006171 · DOI · Paper page
  58. 10.1016/S0006-2952(99)00166-5 · DOI · Paper page
  59. Messenger, 2013, J Clin Aesthet Dermatol., 6, 45
  60. 10.1136/bmj.307.6905.655 · DOI · Paper page

Cited by

Sorted by citations

Authors
Tang, W. H. W., & Hazen, S. L.
Affiliations
Cleveland Clinic (US)
Corresponding author
Hazen, Stanley L.
ORCID
Venue
Journal of Clinical Investigation
Publisher
American Society for Clinical Investigation
Published
2014-10-01
Volume
124
Issue
10
Pages
4204-4211
ISSN
0021-9738 (ISSN-L)
DOI
10.1172/jci72331
PMC
PMC4215189
OpenAlex
W2035837169
Cited by
641
References
24
Citations by year
2026: 29 · 2025: 42 · 2024: 35 · 2023: 37 · 2022: 57 · 2021: 58 · 2020: 67 · 2019: 70 · 2018: 70 · 2017: 83 · 2016: 53 · 2015: 34 · 2014: 5
FWCI
5.49
Type
journal article
Language
en
Open access
Locations
  • Journal of Clinical Investigation (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • Office of Dietary Supplements (R01 HL103866, P20 HL113452)
  • Cleveland Clinic
  • Case Western Reserve University
  • National Institutes of Health (UL1TR000439)
  • National Heart, Lung, and Blood Institute (R01HL103931, P20HL113452, P01HL076491, P01HL098055, R01HL103866)
  • National Center for Advancing Translational Sciences
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Gut microbiota and health
  • Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Nutritional Studies and Diet
  • Life Sciences › Immunology and Microbiology › Immunology › Atherosclerosis and Cardiovascular Diseases
Keywords
gut microbiota, cardiovascular disease, atherosclerosis, trimethylamine, trimethylamine N-oxide, choline, phosphatidylcholine, L-carnitine, flavin monooxygenase 3, dietary nutrients, host-microbe interactions, cardiovascular risk
MeSH terms
Animals, Cardiovascular Diseases, Carnitine, Choline, Diet, Female, Food, Humans, Intestines, Male, Methylamines, Oxygenases, Phosphatidylcholines, Atherosclerosis, 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.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-05.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-05.

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.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review