As our understanding of the relationship between the gut microbiome and human health continues to build, research has illuminated the direct benefits that exercise can bring to the bacteria in our bellies. But some scientists have been wondering if the opposite could also be true, can the makeup of these bacterial communities influence athletic performance? A new mouse study indicates that indeed it can, and raised the prospect of therapeutics that could help get couch potatoes up and about.
The new research carried out by scientists at the University of California, Riverside, builds on another interesting finding from 2019. That Harvard-led study assessed the gut microbiome of 15 elite athletes and found heightened levels of a particular gut bacteria species, which was shown to have a unique preference for lactic acid as a fuel source. Mouse treadmill experiments showed that the presence of this bacteria brought about a significant gains in time-until-exhaustion.
The authors of this new study have been exploring similar questions, wondering whether gut bacteria can impact voluntary exercise behavior. Their work also focused on mice, with one group engineered to be high-level runners and a second normal group used as a control. The mice were given antibiotics designed to kill off essential species of gut bacteria, which was confirmed through fecal samples after 10 days of treatment.
Wheel-running capacity among the athletic mice was reduced by 21 percent as a result, and they didn't recover their high-level running abilities even 12 days after the treatment had stopped. Behavior of the normal mice was not significantly affected by the treatment, and neither group showed any signs of sickness, enabling the team to pin the effects on the missing bacteria.
“We believed an animal’s collection of gut bacteria, its microbiome, would affect digestive processes and muscle function, as well as motivation for various behaviors, including exercise,” said study author Theodore Garland. “Our study reinforces this belief.”
As for how the bacteria, or lack thereof, confers these effects, the scientists believe it is due to the role they play in transforming carbohydrates into chemicals that regulate muscle performance. This raises the possibility that certain microbes could be deployed as therapeutics to increase one's motivation for voluntary exercise, and identifying candidates will be the next step for the researchers.
“If we can pinpoint the right microbes, there exists the possibility of using them as a therapeutic to help average people exercise more,” Garland said.
The Harvard study mentioned above pointed to the possibility of performance-enhancing probiotics. The authors of this new study note this is still an emerging field of study, but say the results do highlight the importance of a healthy diet.
“We do know from previous studies that the western diet, high in fat and sugar, can have a negative effect on biodiversity in your gut and likely, by extension, on athletic ability and possibly even on motivation to exercise,” Garland said.
The research was published in the journal Behavioral Processes.
