As if we needed another reason to work out…

Although it’s well established that diet can change the composition of our microbiome (the universe of bacteria living inside every human that’s believed to influence everything from metabolism to mood), recent studies suggest that exercise can alter it too

In one study, higher self-reported physical activity levels were associated with a 22% reduced risk of active Ulcerative Colitis “UC” (chronic digestive condition), and a 10-wk intervention that included moderate exercise improved quality of life in patients with moderately active UC.

Another study investigated the microbiomes of 40 professional international rugby union players compared to control groups of people of similar age with either high or low BMI. It highlighted “significantly greater intestinal microbial diversity among the athletes”.

And in one recent study, Scientists at the University of Illinois at Urbana-Champaign identified significant differences in the gut bacteria of obese and lean individuals who underwent the same endurance training.

The scientists took blood and fecal samples and tested everyone’s aerobic fitness. Then the volunteers began supervised workouts, during which their efforts increased over time from about 30 minutes of easy walking or cycling to about an hour of vigorous jogging or pedaling three times per week.

They were asked not to change their normal diets.

After six weeks, the scientists collected more samples and retested everyone, and then asked the volunteers to stop exercising altogether.

Six weeks later, the tests repeated.

The results showed that the volunteers’ gut bugs had changed throughout the experiment. In particular, they noted widespread increases in certain microbes that can help to produce substances called short-chain fatty acids. These fatty acids are believed to aid in reducing inflammation in the gut and the rest of the body. They also work to fight insulin resistance, a precursor to diabetes, and otherwise bolster our metabolisms.

Significantly, the study’s overall results suggest that even a few weeks of exercise can alter the makeup and function of our gut microbiome – although consistency is key as almost all of the changes in people’s guts reverted to what they had been at the study’s start after six weeks of not doing any exercise.

The above content is provided for informational and educational purposes only and is not a substitute for professional advice or diagnosis and should never be relied upon for specific medical advice.

Sources:Evans CC, LePard KJ, Kwak JW, et al. Exercise prevents weight gain and alters the gut microbiota in a mouse model of high fat diet-induced obesity. PLoS One. 2014; 9(3):e92193. Allen JM, Miller MEB, Pence BD, et al. Voluntary and forced exercise differentially alters the gut microbiome in C57BL/6J mice. J. Appl. Physiol. 2015; 118(8):1059–66. Morgan XC, Tickle TL, Sokol H, et al. Dysfunction of the intestinal microbiome in inflammatory bowel disease and treatment. Genome Biol. 2012; 13(9):R79. Jones PD, Kappelman MD, Martin CF, Chen W, Sandler RS, Long MD. Exercise decreases risk of future active disease in inflammatory bowel disease patients in remission. Inflamm. Bowel Dis. 2015; 21(5):1063–71.  https://nutrsci.illinois.edu/news/exercise-alters-our-microbiome-one-reason-it’s-so-good-us