Source: University of Illinois at Urbana-Champaign
Summary: Researchers in a new study found that exercise changes the microbial composition of the gut in potentially beneficial ways.
Researchers from the University of Illinois conducted two studies – one in mice and the other in humans. In the first study, they transplanted fecal material from exercised and sedentary mice into the sedentary germ-free mice colons – raised in a sterile facility and had no microbiota of their own. In the second study, they tracked changes in the composition of gut microbiota in human subjects as they transitioned from a sedentary lifestyle to a more active one and back again. Both the studies, offer the definitive evidence, first of its kind, that exercise alone can change the composition of gut microbiota. These exercise-induced changes affecting the gut are independent of other factors such as diet and antibiotic case – that might alter the intestinal microbiota. The study findings were published in the journal Medicine & Science in Sports & Exercise.
In the mouse study, the research team observed that recipients of the exercise mouse microbiota had a larger proportion of microbes that produce butyrate – a short-chain fatty acid (SCFA) which promotes healthy intestinal cells, decrease inflammation and generate energy for the host. And also observed the recipients are more resistant to experimental ulcerative colitis (an inflammatory bowel disease). In the human study, as a result of exercise, fecal concentrations of SCFAs, specifically butyrate was increased in the human gut and these levels declined when the human subjects returned to a sedentary lifestyle. Researchers feel that the changes in the composition of gut microbiota with exercise can be potentially beneficial.
Postdoctoral researcher, Jacob Allen said, “We found that the animals that received the exercised microbiota had an attenuated response to a colitis-inducing chemical”, “There was a reduction in inflammation and an increase in the regenerative molecules that promote a faster recovery.”
Prof. Jeffrey Woods said, “The bottom line is that there are clear differences in how the microbiome of somebody who is obese versus somebody who is lean responds to exercise”, “We have more work to do to determine why that is.
Jacob M. Allen et al, Exercise Alters Gut Microbiota Composition and Function in Lean and Obese Humans, Medicine & Science in Sports & Exercise(2017). DOI: 10.1249/MSS.0000000000001495
M. Allen et al. Exercise training-induced modification of the gut microbiota persists after microbiota colonization and attenuates the response to chemically-induced colitis in gnotobiotic mice, Gut Microbes(2017). DOI: 10.1080/19490976.2017.1372077