Elimination of intestinal microorganisms reduces motivation and ability to exercise.
According to a recent study, antibiotics destroy essential gut bacteria, which destroys motivation and endurance in athletes. According to a mouse study conducted by the University of California, Riverside, a significant differentiator between couch potato athletes is their microbiome.
This study is one of the few to examine how gut bacteria also influence voluntary exercise habits. While other studies have looked at the impact of exercise on the microbiome, this one shows the opposite. Athletic prowess and motivation are required for voluntary exercise.
The researchers’ findings were recently published in the journal Behavioral processes.
“We thought that 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 Theodore Garland, physiologist at UCR evolution in whose laboratory the research was conducted. “Our study reinforces this belief.”
The researchers used fecal samples to demonstrate that after 10 days of antibiotic treatment, the gut bacteria of two groups of mice – those raised for high levels of running and some that were not – were reduced.
Both groups of mice showed no symptoms of disease after antibiotic therapy. The researchers were thus convinced that damage to the microbiota was to blame when wheel rotation in sports mice was reduced by 21%. The high runner mice also did not regain their running behaviors 12 days after the end of antibiotic treatment.
Both during and after treatment, the behavior of normal mice was not significantly altered.
“A casual practitioner with a minor injury wouldn’t be much affected. But on a world-class athlete, a small setback can be amplified much more,” said Monica McNamara, a PhD student in evolutionary biology at UCR and first author of the paper. “That’s why we wanted to compare the two types of mice.” Knocking out the normal gut microbiome could be compared to an injury.
One of the ways the microbiome could affect exercise in mice or humans is its ability to convert carbohydrates into chemicals that pass through the body and affect muscle performance.
“The metabolic end products of bacteria in the gut can be reabsorbed and used as fuel,” Garland said. “Less good bacteria means less fuel available.”
In the future, researchers would like to identify the specific bacteria responsible for increasing athletic performance. “If we can identify the good microbes, there’s the possibility of using them as therapeutics to help average people exercise more,” Garland said.
Lack of exercise is known to be a major risk factor for certain aspects of mental health, including depression, as well as physical health, including metabolic syndrome, diabetes, obesity, cardiovascular disease, cancer and osteoporosis. Many in the public health community would like to promote exercise, but few have found ways to do so successfully.
“Although we study mice, their physiology is very similar to that of humans. The more we learn, the better our chances of improving our own health,” Garland said.
Certain foods can also increase desirable gut bacteria. As research on “probiotics” grows, Garland recommends those interested in promoting overall health maintain a balanced diet in addition to regular exercise.
“We know from previous studies that the Western diet, high in fat and sugar, can have a negative effect on the biodiversity of your gut and probably, by extension, on athletic ability and perhaps even motivation to exercise,” Garland said.
Reference: “Oral Antibiotics Reduce Voluntary Exercise Behavior in Sporting Mice” by Monica P. McNamara, Marcell D. Cadney, Alberto A. Castro, David A. Hillis, Kelly M. Kallini, John C. Macbeth, Margaret P. Schmill, Nicole E. Schwartz, Ansel Hsiao, and Theodore Garland Jr., May 4, 2022, Behavioral processes.