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Gut Bacterial Fatty Acid Cuts Plaque Buildup by Half in Mice

A fatty acid made by gut bacteria lowered cholesterol and shrank artery plaque in mice, pointing to a new angle on heart disease.

By Dr. Axe Editorial Team · October 20, 2026 · 1 source · Watch

A gut bacterial fatty acid reduced atherosclerotic plaque by around 50% in mice, according to a study published October 7, 2026 in Nature.

Researchers found that giving mice Bacteroides uniformis, a bacterial species that is typically depleted in people with atherosclerosis (artery plaque buildup), reduced atherosclerotic plaque burden by around 50% and improved plasma lipid profiles, compared with untreated mice. Working backward from the bacteria's effects, the team identified pentadecanoic acid, a saturated odd-chain fatty acid labeled PA (C15:0), as the main active compound responsible for this benefit. Screening 100 gut bacterial strains, the researchers found PA production occurs across multiple genera within the Bacteroidota group of gut bacteria, not just the one species tested. Separately, the researchers reported that PA is markedly depleted in patients with dyslipidemia (abnormal blood cholesterol or fat levels).

Mechanistically, the study authors report that PA works by directly inhibiting HMG-CoA reductase, the liver enzyme that makes new cholesterol, and in parallel increases hepatic LDL receptor expression, the protein on liver cells that pulls LDL cholesterol out of the bloodstream for disposal. Together, the authors state, these two actions suppress the liver's own cholesterol production while speeding up removal of circulating LDL cholesterol, the combination driving the drop in plaque.

Plaque reduction in treated mice

Nature, 2026, Yin et al.

This is a mouse study, so the plaque reduction and lipid changes have not been shown in humans. The human dyslipidemia finding is an association in patient samples, not a treatment trial, and absolute risk was not reported. No dose, duration or safety data for PA supplementation in humans are available from this record. One author is an inventor on a pending patent application for using PA against atherosclerosis.

Dr. Axe’s Take

This is the gut-liver connection I find compelling: a single bacterial metabolite directly throttles how much cholesterol the liver makes and how fast it clears LDL cholesterol from the blood. That's a mechanism worth paying attention to, even though this is mouse data and no human trial exists yet. My judgment is that feeding the gut bacteria that make compounds like this matters more than chasing any single metabolite. This week, build meals around diverse plant fiber, legumes and resistant starch to support the Bacteroidota population, and keep up with routine lipid panels through your doctor rather than waiting on future human trials of this compound.

— Dr. Axe

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Study summary

Who: Mouse model of atherosclerosis; human dyslipidemia patient samples analyzed for comparison
Design: Laboratory and animal study: bacterial administration, bioactivity-guided compound screening, and a 100-strain gut bacteria survey
Dose: Not reported (Bacteroides uniformis administration and pentadecanoic acid supplementation in mice; no human dose)
Primary result: Atherosclerotic plaque burden reduced by around 50% in treated mice versus untreated mice
Secondary: Plasma lipid profiles improved in treated mice; pentadecanoic acid production found across multiple Bacteroidota genera in 100 strains screened; pentadecanoic acid markedly depleted in human dyslipidemia patients
Funding / conflicts: Funding not reported in the journal or PubMed record. Conflicts declared in the PubMed record: one author is an inventor on a pending patent application covering the use of pentadecanoic acid to prevent or treat atherosclerosis; the other authors declare no competing interests.
Date: Oct 7, 2026