Researchers have started to identify bacteria that may play a role in elite performance by helping athletes get energy from food or break down chemicals that cause soreness.

A Harvard team is planning to sell probiotics based on this research.

But there are are still major questions about whether probiotics work.

Many people have wondered whether some unknown factor sets elite athletes apart — beyond their training regimens, strict diets, and exceptional psychological strength.

New research suggests one distinguishing element could be unique gut bacteria that helps athletes' bodies process food for energy, reduce inflammation, and eliminate chemicals that cause fatigue and soreness.

That's according to a presentation from researchers at the Church Lab at Harvard Medical School, who shared their work August 20 at the national meeting of the American Chemical Society. The scientists are trying to identify these special bacteria and develop probiotic products based on them.

If these products work as planned, they could help others improve their internal microorganisms and cultivate internal physiological traits that enhance athletic performance— all using naturally occurring bacteria.

"When we first started thinking about this, I was asked whether we could use genomics to predict the next Michael Jordan," Jonathan Scheiman, a postdoctoral fellow at Harvard, said in a news release. "But my response was that a better question is: Can you extract Jordan's biology and give it to others to help make the next Michael Jordan?"

There's reason to be skeptical of this effort, however: Probiotic products that can create some ideal bacterial population don't yet exist.

How gut bacteria might affect athletic performance

The Harvard researchers plan to base their forthcoming probiotic on the science of the microbiome, the bacterial community that live in and on us. While there are a number of myths about the microbiome, most researchers believe that our microbial populations play an essential role in various aspects of human health.

As Scheiman explained in a press briefing at the conference, "this collective community, in particular in the gut, greatly influences our health, development, functionality, even has implications in disease for processes such as energy metabolism, protein metabolism, neurology, and immunology."

Various factors influence our internal bacteria, including what we eat, how we exercise, and genetics. The Harvard researchers wanted to see what sorts of bacterial communities were most closely associated with specific groups of athletes.

Scheiman and team recruited elite athletes from a number of sports — participants included marathoners, ultramarathoners, and elite rowers. The researchers sequenced the athletes' internal microbiomes, and tracked them over time to see how their bacteria changed while they were competing, training, and resting.

In a group of 20 marathoners running the Boston Marathon, they found that populations of a certain bacteria spiked after the race, especially when compared to the gut bacteria of 20 healthy non-racers. That particular microbe breaks down lactic acid, which is produced during physical activity and makes people feel fatigued and sore. High levels of that that bacteria could have helped the runners push harder through the race.

The researchers also found that athletes from different sports have different sorts of internal bacteria. Ultramarathoners, who need to eat and process food during competition, had an especially high concentration of microbes that break down and make use of carbohydrates and fiber. But they didn't find those same concentrations in Olympic rowers.

The researchers are now trying to see if providing these bacteria — eventually in the form of a probiotic pill — can increase athletic performance. For their next studies, they are starting with mice.

Can it really work?

Scheiman explained at the conference that he hopes the biology of the athletes he's studied could help regular people figure out how to change their own microbiomes in beneficial ways.

"In essence, we're mining the biology of the most fit and healthy people in the world and then extracting that information to help them and others," he said.

But there are still questions about whether simply taking a probiotic could make a difference.

Hopes for miraculous probiotics have been high ever since researchers figured out that gut bacteria populations change over time, and that the presence or absence of certain bacteria is connected to traits like athletic performance, obesity, and anxiety. Researchers have told Business Insider they think new probiotics have the potential to improve health. But they've also acknowledged that there's little evidence to suggest we know how to make such probiotics work effectively.

Probiotics have been shown to help with a few specific health conditions, like preventing a serious intestinal disease in premature infants or treating a C. difficile infection. But there's not much evidence that probiotics treat the vast majority of conditions they are advertised for.

Although the microbiome can change rapidly, we're not good at directing that process. Most of the time, newly introduced bacteria don't successfully colonize a gut, Ian Orme, a professor of microbiology at Colorado State University, previously told Business Insider.

We're not even very good at altering our microbiomes by changing what we eat. "So far, we have limited evidence of how particular nutrients, foods or dietary patterns influence the gut microbiota," John Mathers, the director of the Human Nutrition Research Center at Newcastle University, told Business Insider.

Although the Harvard team is identifying bacteria that could help successful athletes, they don't necessarily know yet that an ideal bacterial community for ultrarunners exists or that changing someone's internal flora will make them a better rower or runner.

Despite these challenges, the researchers plan to launch a company called Fitbiomics to produce probiotics this fall.

"I would like to think that a year after we launch, we could have a novel probiotic on the market," Scheiman said.

But until the team demonstrates that it's possible to use bacteria to boost one's health or physical performance, the best thing an aspiring athlete can do is keep practicing and eating well.