Gut bacteria can help you stay motivated to exercise
“If we can confirm the presence of a similar pathway in humans, it could offer an effective way to increase people’s fitness levels in order to improve general public health.” Lead author of the study Christoph Thaiss, PhD, assistant professor of Microbiology. at Penn Medicine.
Thaiss and colleagues set up the study to search extensively for the determinants of exercise performance. They recorded genome sequences, gut bacteria species, blood metabolites and other data for genetically diverse mice. They then measured the animals’ daily voluntary wheel runs, as well as their endurance.
The researchers analyzed these data using machine learning, looking for attributes of the mice that could best explain the significant differences between individuals of animals in running performance. They were surprised to discover that genetics seemed to account for only a small part of these performance differences—while differences in gut bacteria appeared to be much more important. In fact, they observed that giving mice broad-spectrum antibiotics to eliminate their gut bacteria halved the mice’s running performance.
Gut bacteria can boost exercise performance
Finally, in a course of years of scientific research involving more than a dozen separate laboratories in Penn and elsewhere, researchers have discovered that two species of bacteria are linked. closely together for better performance, rectal bacteria and Coprococcus euctutus, which produces metabolites known as fatty acid amides (FAA). The latter stimulates receptors called CB1 endocannabinoid receptors on sensory nerves in the gut, which connect to the brain via the spine. Stimulation of these CB1-receptor nerves causes an increase in the levels of the neurotransmitter dopamine during exercise, in an area of the brain called the ventral striatum.
The striatum is an important node in the brain’s motivation and reward network. The researchers concluded that the extra dopamine in this area during exercise boosts performance by reinforcing the desire to exercise.
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 an entirely new branch of exercise physiology.”
These findings open up many new scientific research directions. For example, there is evidence from experiments that better-performing rats experience more intense ‘highs’—measured in this case by a decrease in pain sensitivity—suggesting that the phenomenon This well-known fact is at least partially controlled by the gut. bacteria. The team is now planning further studies to confirm the existence of this gut-to-brain pathway in humans.
In addition to being able to provide inexpensive, safe, diet-based methods to help ordinary people run and optimize the performance of elite athletes, he added. This pathway may also provide easier methods for regulating motivation and mood in situations such as addiction and depression.