A probiotic pill could trick your body into exercising like a pro

Fitness pills that promise instant athleticism – and the beach-ready body to go with it – may be wishful thinking, but new research suggests athletes could be carrying the key to better exercise for the rest of us around in their stomachs. A new study explores just what's going on in the gut bacteria of competitive runners, and why key parts of the microbiome there had a huge impact on performance when transplanted into another runner.

Now, before you get too excited about the prospect of running a marathon with no prior training, it's worth noting that the other runner in this particular case was a mouse, not a human. The study, published this week in the Nature Medicine journal, spotted that a certain bacterial strain common in successful human runners could, when introduced into mice colons, significantly boost their performance on treadmills.

Regular mice, without the bacterial transplant, were pit against the test mice. The latter group lasted 13-percent longer, on average, across all the trials. That has researchers excited about the potential for improving human performance.

The bacteria in question is Veillonella, which feasts on lactate. That's a byproduct of exercise, and thus particularly prevalent in the digestive system of competitive runners. When researchers at the Joslin Diabetes Center compared stool samples of runners from the Boston Marathon with those from sedentary individuals, Veillonella proved to be the obvious difference.

Just throwing some extra Veillonella into mice wasn't enough, however. The mechanism by which the bacteria impacts performance took some digging, but eventually it was narrowed down to what happened after it metabolites lactic acid. That, it turns out, promotes the generation of propionate, a short chain fatty acid.

"We did some experiments to introduce propionate into mice [via enema] and test whether that was sufficient for this increased running ability phenotype. And it was," Aleksandar D. Kostic PhD, Assistant Investigator in the Section on Pathophysiology and Molecular Pharmacology, and a co-author of the new study, says of the trials.

Just packaging propionate into a pill, however, won't work. The problem there is that digestive juices would break down the fatty acid before it could have any impact, the team says. Instead, it would take something like a probiotic capsule that contains Veillonella, and which could kick-start the whole process.

A spin-off company has been set up to explore commercial applications of that, though further research trials are needed to make sure this is not just going to be of benefit to mice. Still, the prospects are significant, assuming later testing concurs. Not only could such probiotics help would-be athletes increase their performance, but it might be beneficial for those who struggle to maximize the health impact of what exercise they do.

People with metabolic disorders, the researchers point out, often have issues trying to meet their recommended exercise goals. While fitness training is known to help avoid or minimize the impact of things like type 2 diabetes, it relies on a certain level fo exercise to be effective. If a probiotic based on Veillonella could supercharge those exercise sessions, it may have a valuable role in reducing illness.