A new study with rats shows that exercising early in life can alter the microbial community in the gut, promoting healthier brain and metabolic activity over the course of a lifetime.
“Exercise affects many aspects of health, both metabolic and mental, and people are only now starting to look at the plasticity of these gut microbes,” said Dr. Monika Fleshner, a professor at the University of Colorado at Boulder and the senior author of the new study. “That is one of the novel aspects of this research.”
Microbes take up residence within human intestines shortly after birth and are vital to the development of the immune system and various neural functions, Fleshner said. These microbes can add as many five million genes to a person’s overall genetic profile, giving them tremendous power to influence aspects of human physiology.
While this microbial community remains somewhat malleable throughout adult life and can be influenced by environmental factors such as diet and sleep patterns, the researchers found that gut microorganisms are especially “plastic” at a young age.
The study found that juvenile rats who voluntarily exercised every day developed a more beneficial microbial structure, including the expansion of probiotic bacterial species in their gut compared to both their sedentary counterparts and adult rats, even when the adult rats exercised as well.
The researchers have not, as of yet, pinpointed an exact age range when the gut microbe community is likeliest to change, but the preliminary findings indicate that earlier is better.
A robust, healthy community of gut microbes also appears to promote healthy brain function and provide antidepressant effects, according to Fleshner.
Previous research has shown that the human brain responds to microbial signals from the gut, though the exact communication methods are still under investigation.
“Future research on this microbial ecosystem will hone in on how these microbes influence brain function in a long-lasting way,” said Agniezka Mika, a graduate researcher in University of Colorado, Boulder’s Department of Integrative Physiology and the lead author of the new study.
The researchers next plan to explore ways of encouraging positive gut microbe plasticity in adults, who tend to have stable microbial communities that are more resistant to change.
The study was published in the journal Immunology and Cell Biology.