According to an innovative new study by researchers at University College Cork, part of the National University of Ireland being physically fit can encourage germs in your gut to keep you healthy and frequent exercise may influence our weight and overall health by altering the kinds of organisms that live inside of us.

These studies have shown that people with large and diverse germ populations in their digestive tracts tend to be less prone to obesity, immune problems and other health disorders than people with low microbial diversity, and that certain germs, in particular, may contribute to improved metabolic and immune health.

“We chose professional athletes as a study group, because we wanted to be sure not to miss any effect of exercise and needed a group who were safely performing at the extremes of human endeavor,” said Dr. Fergus Shanahan, an author of the study who is a professor of gastroenterology and director of the Alimentary Pharmabiotic Center at University College Cork, where 40 rugby players had agreed to participate in this study.

The gut and intestines of the athletes was quite different from that of the other normal men in either of the control groups. The rugby players had considerably more diversity in the make-up of their gut micro biomes, meaning that their intestinal tracts hosted a greater variety of germs than did those of the other men, especially the men in the group with the highest B.M.I.

These findings “draw attention to the possibility that exercise may have a beneficial effect on the micro biota,” Dr. Shanahan said, in ways that improve bodily health. Either ways exercise in any amount is always beneficial to the body and the bacteria residing there.