Some species of bacteria that live in the gut activate nerves in the gut to promote the desire to exercise, according to a mouse study led by researchers at the Perelman School of Medicine at the University of Pennsylvania. The study, published in the journal Nature, reveals the gut-brain pathway that explains why some bacteria improve exercise performance.
In the study, researchers found that differences in running performance among a large group of lab mice were largely attributable to the presence of certain gut bacterial species in the better-performing animals. The researchers traced this effect to small molecules called metabolites that the bacteria produce—metabolites that stimulate sensory nerves in the gut to boost activity in a brain region that controls motivation during exercise.
"If we can confirm the presence of a similar pathway in humans, it could provide an effective way to increase people's exercise levels to improve overall public health," said the study's lead author, Christoph Thaiss, Ph.D., assistant professor of Microbiology at Penn Medicine.
They were surprised to find that genetics only seemed to explain a small portion of these performance differences, while differences in gut bacterial populations seemed to be much more important. In fact, they observed that giving mice broad-spectrum antibiotics to eliminate gut bacteria reduced the mice's running performance by about half.
"This gut-to-brain motivation pathway could have evolved to connect nutrient availability and the state of the gut bacterial population to the willingness to engage in prolonged physical activity," said study co-author J. Nicholas Betley, Ph.D., associate professor of biology at the University of Pennsylvania's School of Arts and Sciences. "This line of research could evolve into a whole new branch of exercise physiology."
Conclusions: The balance of gut microbiota is essential for the normal functioning of the human body. Restoration of the microbiota could reduce neurodegeneration and improve cognitive function among AD patients. Furthermore, distinctive gut microbial profiles could help predict AD risk. Restoration of the gut microbiota through dietary modifications, probiotic supplementation, and FMT could also improve cognition and, as a result, offer potential therapeutic strategies for the treatment of AD.
