Endurance training may alter our microbiome for good, according to a recent study.

The rich mix of bacteria that fosters a healthy gut microbiome thrives on a nutritious diet, but it may also get a boost from a good workout: Finnish researchers have found that endurance training may increase levels of a type of microbe that improves metabolic function while trimming the population of its inflammatory neighbors.

The research team recruited 17 overweight and sedentary women for the study and led them through three training sessions per week for six weeks using a stationary bike. Participants made no dietary or other lifestyle changes during that time. Researchers analyzed fecal samples submitted prior to and during the study to monitor changes to the women’s microbiomes.

They found that the exercise routine reduced the amount of Proteobacteria microbes, which decreased the inflammation-producing action of certain lipids. The training regimen also tended to lower levels of phospholipids and cholesterol in VLDL (or very-low-density lipoprotein particles). And because VLDL, which transports lipids from the liver to peripheral tissues, converts into LDL cholesterol in the bloodstream, those lower levels improved cardiometabolic health in the participants.

Boosting the metabolic-friendly population of Akkermansia microbes may have suppressed vascular adhesion protein-1 activity, which can yield anti-inflammatory benefits (more research is needed to confirm that thesis).

Although the six-week regimen didn’t produce dramatic changes in the number of either microbe, it did offer encouragement for future investigation.

“Based on our data and existing literature, we propose that especially Akkermansia and Proteobacteria are exercise-responsive taxa,” lead study author Eveliina Munukka notes in Frontiers in Microbiology. “Our results [suggest] the need for further studies in larger cohorts to determine whether exercise types other than endurance exercise also modify the gut metagenome.”