Coronary artery disease: microbiota metabolites associated with prognosis, without evidence of treatment benefit

What the researchers studied

The review focuses on patients with coronary artery disease, not a healthy population. The researchers searched for prospective studies linking microbiota characteristics or metabolite concentrations to prognosis. Their literature search covered studies up to January 21, 2026.

The events studied included deaths, heart attacks, strokes, unstable angina, heart failure and unplanned hospitalizations or emergency department visits. This grouping combines outcomes of varying severity: an association with this composite does not necessarily mean an identical association with each of its components.

The dossier provides access only to the PubMed abstract. The total sample sizes, follow-up durations and details of the comparisons are not available in this excerpt.

Different associations depending on the metabolites

Trimethylamine N-oxide, or TMAO, emerges as a marker associated with an unfavorable prognosis. The abstract reports a consistent concentration–risk association: higher concentrations were linked to more events. However, it provides no numerical estimate to assess the magnitude of the risk.

Phenylacetylglutamine and imidazole propionate were also associated with worse outcomes in patients who had experienced an ST-segment elevation myocardial infarction. Conversely, indole-3-propionic acid was associated with lower mortality. These findings concern specific populations and cannot be directly extrapolated to people without coronary artery disease.

Among bacteria, a greater abundance of Lactobacillus was associated with a favorable prognosis. This does not demonstrate that a probiotic supplement containing lactobacilli would produce the same effect: observing a bacterium in the microbiota and administering a product are two distinct situations.

A research signal, not a validated strategy

The review discusses several possible mechanisms, including inflammation, lipid metabolism, endothelial function and platelet activation. These avenues are biological hypotheses explaining the associations, not proof that targeting these metabolites prevents a cardiovascular event.

Following patients over time allows researchers to study the link between a marker and subsequent events, but is not enough to establish causality. The abstract does not allow a detailed assessment of confounding factors, study quality or heterogeneity.

These findings justify further evaluation of prognostic markers and potential therapeutic targets. They are not sufficient to recommend microbiota testing, TMAO measurement or a supplement to improve coronary prognosis.

What we can take away

Certain microbiota metabolites are associated with outcomes in patients with coronary artery disease. The review does not demonstrate that modifying their concentrations improves patients’ health.