Some species of gut-dwelling bacteria activate nerves in the gut to promote the desire to exercise, according to a study in mice that was led by researchers at the Perelman School of Medicine at the University of Pennsylvania. The study was published [December 14] in Nature, and reveals the gut-to-brain pathway that explains why some bacteria boost exercise performance.
In the study, the researchers found that differences in running performance within a large group of lab mice were largely attributable to the presence of certain gut bacterial species in the higher-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 enhance activity in a motivation-controlling brain region during exercise.
The team now plans further studies to confirm the existence of this gut-to-brain pathway in humans.
Apart from possibly offering cheap, safe, diet-based ways of getting ordinary people running and optimizing elite athletes’ performance, he added, the exploration of this pathway might also yield easier methods for modifying motivation and mood in settings such as addiction and depression.
