A study published in Nature on 7 October points to a gut bacterium that may do part of statins' job — and explains how. Researchers led by Wenjing Zhao, a microbiologist at Sun Yat-sen University in Shenzhen, China, found that Bacteroides uniformis, a microbe common in the human gut, produces pentadecanoic acid, a fatty acid that suppresses cholesterol production.

The mechanism is familiar from medicine's most-prescribed drugs. Pentadecanoic acid inhibits HMG-CoA reductase, the same liver enzyme that statins block. Blocking it prompts the liver to build more LDL receptors, which pull excess cholesterol out of the bloodstream. In genetically engineered mice fed a high-fat diet to model atherosclerosis, being given live B. uniformis shrank arterial plaque by about a third — and by about half in one measurement Nature's news team reported — lowered total cholesterol and LDL, the "bad" cholesterol, and reduced the inflammatory immune cells infiltrating artery walls.

The human data is suggestive but not yet causal. Zhao's team analysed stool and blood from more than 200 donors and found that B. uniformis was depleted in people with cardiovascular disease, and that those with high blood-fat levels carried less pentadecanoic acid and fewer bacterial genes for making it. That is a correlation; a trial would be needed to show the molecule lowers cholesterol in people. Ben Chen, a cardiovascular specialist at the Monash Victorian Heart Institute in Melbourne, called the work "valuable evidence that the gut microbiome can influence vascular health," moving from simple association toward "evidence for a potentially causal biological mechanism."

The stakes are large. Atherosclerosis — the buildup of inflammatory plaques in artery walls — remains the leading cause of death worldwide, and statins alone fail to lower cholesterol enough in nearly half of people with advanced heart disease, while some cannot tolerate high doses. A microbiome-based route would not replace statins, but it suggests a new lever. The open questions are practical: can pentadecanoic acid, or a B. uniformis-based intervention, be delivered safely and at the right dose, and will the mouse results hold in humans?

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