THE WASHINGTON POST - While we know that exercise can influence the health of the microbiome, it’s much less clear whether the effects work the other way, and your microbiome can influence your exercise. Anecdotally, people and lab mice taking antibiotics don’t exercise much, but the reason might be that they probably felt ill before starting the drugs, discouraging physical activity.
So, scientists at the University of California at Riverside decided to wipe out the microbiomes of mice that love to run and see how they’d respond. The UC-Riverside mice were part of an ongoing experiment in which female mice, that ran more than their lab mates, were bred to male mice of the same persuasion. Over multiple generations, the scientists developed a strain of super-runner mice. These animals voluntarily ran on wheels about three times as much as other mice. They also developed different microbiomes.
Now, for a study published last year in Behavioural Processes, the scientists gave some of these marathon mice broad-spectrum antibiotics, to kill off most of their gut bacteria. The animals continued to eat and otherwise live in unchanged ways, indicating the antibiotics hadn’t sickened them.
But when the researchers gave the animals free access to running wheels, the marathoner mice’s running mileage fell steeply. They averaged about 21 percent less distance every day, numbers that barely rebounded during the subsequent 12 days of the study.
The new experiment underscored “just how much” the microbiome seemed to be influencing the athletic animals’ willingness to run, said Theodore Garland, an evolutionary biologist at UC-Riverside, whose lab developed the marathon mice and who oversaw the new study.