News : A study detects a microbe that improves the performance of athletes

A study published in the journal 'Nature Medicine' conducted with elite runners has identified a group of bacteria that are more common in athletes, especially after exercise, and that may play a role in improving sports performance. The researchers isolated this microbe, extracted it from the athletes and experimented it with laboratory mice, reaching the conclusion that these bacteria derived from humans increased mouse performance on a treadmill stress test by 13%.

"This is a really impressive study," says Morgan Langille, a microbiome researcher at Dalhousie University in Nova Scotia who was not involved in the research. Scientists already knew that the exercise subtly changes the composition of our microbiome. Certain strains flower in the post-workout intestine. But they had not shown if any of these exercise-loving microbes affect our health or performance.

"If we could identify the microbes that contribute to the health and performance of the super people, maybe we could develop a probiotic to help people on 'walk' to perform better," says Jonathan Scheiman, currently co-founder and CEO of FitBiomics, who led this study while serving as a postdoctoral researcher at the Harvard Medical School.

Pick up feces in the Boston Marathon

For the research, Scheiman needed a good data set of the intestinal microbes of the athletes. So he asked the runners of the Boston Marathon if he could collect his feces. "I spent two good weeks of my life touring Boston with a Zipcar collecting stool samples from the athletes ", says Scheiman, who wanted to check the microbes before and after the test and compare them with the microbiomes of non-runners.

Scheiman gave stool samples to his colleague Aleksandar Kostic, a microbiologist at the Joslin Diabetes Center at Harvard Medical School (Kostic is also a co-founder and scientific advisor to FitBiomics). Kostic sequenced the bacterial DNA in the stool samples and looked for differences, either in the types of bacteria present or in their relative number, between the groups.

Veillonella, the bacterium of discord

The differences were subtle. "It's not as if the runners' microbiome looks completely different from non-runners," he says. "But a group of bacteria stood out in the corridors. Veillonella ". LThe bacterium Veillonella seemed to be a little more common in runners than in non-runners, and it became much more common after running the marathon. "We were intrigued, but I did not know anything about the Veillonella," says Scheiman. "So I looked it up in Google."

He learned that Veillonella has a rather unusual way of making a living: he eats lactate, a chemical by-product of intense exercise that is associated with fatigue (although, contrary to popular belief, it does not actually damage muscles). Scheiman's intrigue grew. "Is not it interesting that after running a race you have an increase in a type of bacteria Who eats a metabolic by-product of running a race? ... That was a great moment of enlightenment, "he says.

So they did an experiment. Scheiman isolated the Veillonella from the stool of one of the marathoners and transferred it to the entrails of the normal laboratory mice. As a control, he inoculated another group of mice with a different strain of bacteria that do not eat lactate.

Then, the two groups faced each other in a series of races to exhaustion. The mice treated with Veillonella won. On average, they lasted 13% longer (18 minutes vs. 16 minutes in all trials) than control mice. "We were very surprised to see the great effect of a bacterium (derived from humans)," says Scheiman. "Imagine telling a marathon runner that he could improve his performance by 13%. It would be huge. "

Of course, a 13% increase in mice is not directly applied to humans. But the researchers wanted to know how the bacteria that live in the gut (not in the muscles or lungs, the tissues directly involved in exercise) improved the performance in mice so significantly. The research team thought it might have something to do with how Veillonella breaks down lactate.

Hope to be able to benefit one day

Our liver processes the excess lactate by turning it into glucose, but Veillonella does something different. It swallows lactate and converts it into a molecule called propionate, a short-chain fatty acid that has been shown to affect heart rate and oxygen uptake in mice. With this in mind, the researchers transferred pure propionate to the entrails of the mice and performed the same test on a treadmill. "Propionate produced the same resistance impulse as Veillonella," says Scheiman.

The researchers found the mechanism. Veillonella improves the performance of its host by converting lactate to propionate. But why bacteria do this is a difficult question to answer. "Athletes who exercise often may be simply creating an intestine with higher levels of lactate that allow Veillonella to flourish," says Scheiman.

Veillonella may even be pumping propionate to improve its host's performance in symbolic combat, according to Scheiman, although that is not clear. Either way, Scheiman hopes that athletes can one day benefit from their relationship with our guts.