The research, which was recently published in the journal Immunology and Cell Biology, indicates that there may be a window of opportunity during early human development to optimize the chances of better lifelong health.
Microbes take up residence within human intestines shortly after birth and are vital to the development of the immune system and various neural functions. These microbes can add as many 5 million genes to a person's overall genetic profile and thus have tremendous power to influence aspects of human physiology.
While this diverse 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 anti-depressant effects, author said. Previous research has shown that the human brain responds to microbial signals from the gut, though the exact communication methods are still under investigation.