THE ESSENTIAL
- Our digestive tract is home to no less than 1013 micro-organisms (more than a billion) according to Inserm, or as many as the number of cells that make up our body.
- This set of bacteria, viruses, parasites and non-pathogenic fungi constitutes our intestinal microbiota (or intestinal flora).
- According to several studies, the intestinal microbiota has important influences on behavior and it is possible to act on these effects by manipulating it.
Certain species of gut bacteria activate the nerves in the gut to promote the urge to exercise. This is revealed by a new study involving mice, conducted by researchers at the Perelman School of Medicine at the University of Pennsylvania and published yesterday in the journal Nature.
Certain gut bacteria are linked to better athletic performance
In trying to better explain the large differences in running performance among a large group of lab mice, the researchers were surprised to find that genetics only seemed to explain a small part of it. The study authors found that these differences were largely attributable to the presence of certain gut bacterial species in the top-performing animals. They also observed that giving the mice antibiotics to get rid of their gut bacteria halved the running performance of the mice.
After several years of work, the scientists identified two bacterial species that were closely linked to these better performances: Eubacterium rectale et Coprococcus eutactus. These two species of bacteria produce small molecules, more precisely metabolites, called “fatty acid amides”. These metabolites would stimulate sensory nerves in the intestine to improve activity in a region of the brain that controls motivation during exercise (the striatum) by notably causing an increase in dopamine levels.
Dopamine is a neurotransmitter, which plays a fundamental role in the brain’s reward and motivation network. The researchers concluded that the extra dopamine in this brain region during exercise boosts performance by increasing the desire to exercise.
An effective way to improve public health through sport
“If we can confirm the presence of a similar effect in humans, this could offer an effective way to increase people’s exercise frequency to improve general public health.”said the study’s lead author, Christoph Thaiss, an assistant professor of microbiology at the University of Pennsylvania, in a communiqué.
In addition to potentially offering cheap and safe ways to make it easier for people to motivate themselves to play sports and optimize athlete performance, continuing to explore these findings could also provide simpler methods for influencing motivation and mood to combat addiction and depression. The research team plans to carry out other studies to improve knowledge on this subject in the coming years.