Scientists have long known that the human gut is home to over 100 trillion microorganisms, but now University of Colorado Boulder scientists have discovered that exercising early on in life can alter these microbes in a positive manner. In turn, this promotes a 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," Monika Fleshner, senior author of the study, said in a press release. "That is one of the novel aspects of this research."

After birth, microbes take residence in the human intestines are become a key player in the development of the immune system and proper neural functioning. Although this group of microbes is fairly malleable through out adult life and can be altered through diet and sleep patterns, the results of the recent study have discovered that microorganisms exhibit a high level of plasticity at a young age.

In the study, the researchers found that juvenile rats who voluntarily exercised daily developed a more beneficial microbial structure, as opposed to their sedentary counterparts and adult rats, even when adult rats exercised.

Although the researchers have not yet pinpointed the exact age range when the gut microbes are most plastic, the results from the current study suggest that the earlier, the better.

"Future research on this microbial ecosystem will hone in on how these microbes influence brain function in a long-lasting way," said Agniezka Mika, lead author of the new study.

The researchers plan to continue to explore ways to stimulate positive gut microbe plasticity in adults who possess microbe communities that are more resistant to change.

The findings were published in the Dec. 9 issue of Immunology and Cell Biology.