There is certainly no shortage of studies in humans that show doing moderate to vigorous exercise such as running, cycling and resistance training may potentially increase the diversity of bacteria in the guts. This has been linked to better physical and mental health. Doing aerobic exercises for as little as 18-32 minutes, coupled with resistance training three times a week, for a total of eight weeks could make a difference.
Athletes also tend to have increased gut microbial diversity compared to sedentary people, although some of this could be due to the specialised diets that competitors often have too. But a number of studies have shown that the combination of exercise and diet can boost Faecalibacterium prausnitzii numbers and the production of butyrate in active women, often with improved gut function.
But it is still not clear exactly how exercise leads to changes in the community of microorganisms living in our guts, although there are several theories, says [researcher Jeffrey] Woods.
“Lactate is produced when we exercise, and this could be serving as fuel for certain bacterial species,” he says. Another potential mechanism, he explains, could be through exercise-induced alterations in the immune system, especially the gut immune system, as our gut microbes are in direct contact with the gut’s immune cells.
