Lack the Energy for Exercise? Discover a Surprising Reason to Get Moving

Exercise reduces the risk of diseases when done frequently. Now, a research team from the University of Illinois offers another reason to engage in physical activity. Their data shows that exercise has a positive impact on gut bacteria.

According to two recently published studies, exercise led to changes in gut bacteria, which positively affected physiological processes, including metabolism, the immune system, and behavior.

The researchers hypothesize that exercise increases the number of bacteria that produce butyrate, a short-chain fatty acid that benefits intestinal cells, provides energy to cells, and boosts the feeling of satiety. Previously, this fatty acid was found to improve insulin response and influence brain structure. It's surprising to learn that individuals who exercise regularly have higher concentrations of short-chain fatty acids compared to less active people.

In the second study, the effect of exercise on gut bacteria was examined among both men and women, whether overweight or slim. Participants who were previously inactive were asked to engage in exercise for about six weeks and then return to their previous lifestyle for another six weeks.

Samples collected from participants showed changes in gut bacteria according to the participant's obesity level due to exercise.

The data revealed a significant difference between the gut bacteria of overweight and slim participants, with each population responding differently to exercise. In slim individuals, exercise encouraged bacteria that produce short-chain fatty acids, coinciding with an increase in muscle mass at the expense of fat. The rise in short-chain fatty acid production helped grow muscle tissues. Since the gut bacteria composition reverted to previous states when participants returned to a non-exercising routine, the researchers concluded that sustained physical activity is necessary to maintain these beneficial effects.

To their surprise, researchers found that overweight participants already had higher levels of short-chain fatty acids compared to slim participants, even before starting exercise. Thus, the improvement in short-chain fatty acid amounts due to exercise was less significant compared to slim participants. Additionally, high levels of butyrate in overweight individuals were also associated with higher muscle mass and lower fat mass, indicating a marker for a healthier body composition and, naturally, better physical fitness.