Regular exercise in early childhood can make a major difference to metabolism and brain health over the course of a lifetime, according to new findings.

Researchers at the University of Colorado Boulder have found that physical activity during early human development may capitalise on a ‘window of opportunity’ when gut microorganisms are at their most malleable, helping to promote healthier brain and metabolic activity throughout their lives. The researchers have not yet pinpointed an exact age range when the gut microbe community is likeliest to change, but the preliminary findings indicate that earlier is better.

Their study, which has been accepted for publication in the journal Immunology and Cell Biology, found that juvenile rats who voluntarily exercised every day developed stronger metabolisms compared to both their sedentary counterparts and adult rats, even when the adult rats exercised as well.

“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 Monika Fleshner, a professor in CU-Boulder’s Department of Integrative Physiology and the senior author of the new study.

With the human gut harbouring more than 100 trillion microorganisms, the researchers say these microbes are vital for metabolic activity and also appear to promote healthy brain function and provide anti-depressant effects. 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 home in on how these microbes influence brain function in a long-lasting way,” said Agnieszka Mika, a graduate researcher in CU-Boulder’s Department of Integrative Physiology and the lead author of the new study.

The findings highlight the importance of continuing the battle to overcome youth inactivity, while the metabolic benefits highlighted could have additional implications in tackling child obesity. The researchers also plan to explore novel means of encouraging positive gut microbe plasticity in adults, who tend to have stable microbial communities that are more resistant to change.