Posted 2/7/2018 9:00 PM (GMT -6)
"Exercise alone alters our gut microbiota
"It is well established... that what we eat affects the microbes that live in our intestine, collectively known as the gut microbiota. According to two new studies, however, exercise has the same effect.
"In mouse and human experiments, researchers found that physical activity — independent of diet — alters the composition of gut microbiota in a way that increases the production of short-chain fatty acids (SCFAs) that are beneficial for health.
"...mice that received fecal material from the exercise group had higher levels of gut microbes that produce an SCFA called butyrate, which is known to reduce inflammation and promote gut health.
"Additionally, when these mice were given a chemical that triggers colitis, or inflammation of the colon, the researchers witnessed a surprising response. "There was a reduction in inflammation and an increase in the regenerative molecules that promote a faster recovery," says study co-leader Jacob Allen, who was at the University of Illinois at Urbana-Champaign at the time of the research.
"The second study — published in the journal Medicine & Science in Sports & Exercise — included 32 sedentary adults, of whom 18 were lean and 14 were obese.
"...all participants experienced an increase in SCFA levels — especially butyrate — following the 6-week exercise program, but these levels declined when subjects reverted to sedentary behavior.
"With the help of genetic testing, the researchers found that the increase in SCFA levels correlated with alterations in the levels of gut microbes that produce SCFAs, including butyrate.
"Lean subjects saw the greatest increases in SCFA-producing gut microbes after exercise, the team reports, noting that their levels were much lower at baseline. Subjects who were obese experienced "modest" increases in gut microbes that produce SCFAs.
"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." - Jeffrey Woods, lead researcher
"Overall, the researchers believe the findings of both studies provide firm evidence that exercise alone — independent of diet — can alter the composition of gut bacteria."