Research

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Dietary intake of choline, carnitine, and TMAO from foods like red meat, eggs, and marine fish is converted by gut bacteria into trimethylamine (TMA), which is then oxidized by the host enzyme FMO3 into trimethylamine N-oxide (TMAO), a metabolite implicated in cardiovascular disease and metabolic disorders.

Your gut bacteria convert nutrients from foods like red meat, eggs, and fish into TMA, which your liver turns into TMAO. High TMAO levels are linked to heart disease risk. To manage this, focus on dietary variety and gut health, as not all sources (like betaine) produce TMA, and individual microbiome differences affect how much TMAO you produce.

GoodSupportsHIGH confidence
TMA is derived from the diet by microbial degradation of precursors found in, for example, marine fish, eggs, offal, soya beans, peas, and red meat... TMA is rapidly absorbed and is converted in the liver to trimethylamine N-oxide (TMAO)... TMAO has been implicated in various conditions affecting health, including cardiovascular disease, reverse cholesterol transport, and glucose and lipid homeostasis.
Diede Fennema et al. · Drug Metabolism and Disposition · 2016

Why this rating

High-quality review paper citing multiple primary studies and establishing a clear mechanistic pathway, though it does not present new clinical trial data itself.

Source

Trimethylamine and Trimethylamine N-Oxide, a Flavin-Containing Monooxygenase 3 (FMO3)-Mediated Host-Microbiome Metabolic Axis Implicated in Health and Disease

Diede Fennema et al. · Drug Metabolism and Disposition · 2016

DOI 10.1124/dmd.116.070615

narrative_reviewCited 355×
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DOI resolved against Crossref · corpus check 2026-06-10

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