For elite athletes, training often goes beyond daily workouts and into the world of supplements that help make them stronger, fitter and faster. Some supplements, like vitamins and probiotics, are OK in the world of competitive sports. Others, like blood transfusions, are not.

Although it doesn't quite exist just yet, "poop doping" might be the next big thing in performance enhancement.

It all has to do with what's going on in your gut.

Microbiologist and competitive cyclist Lauren Petersen actually stumbled upon the idea of poop doping through personal experience in understanding the microorganisms in her body. When Petersen, a researcher at the Jackson Laboratory for Genomic Medicine in Farmington, Connecticut, was just 11 years old, she contracted Lyme disease. She spent the next several years on different antibiotics. While the medication worked, it also wiped out the beneficial microbes living in her gut. She was sick on and off for a decade, which she attributed to her weakened immune system.

Her interest in microorganisms led her to pursue a career in microbiology. When she was a graduate student, Petersen had her digestive system tested and learned that her gut was not only deficient in good microbes but filled with destructive pathogens such as E.coli and Salmonella.

Unable to find a doctor that would help, Petersen gave herself a fecal transplant from a competitive cyclist with the hope that she could alter the microorganisms in her body. Before the transplant, Petersen could barely squeak out two bike rides a week. Within a few months of the procedure, Petersen felt so good that she was able to train on her bike five days a week. Before she knew it, she was winning races and cycling like never before.

"I wondered if I had gotten my microbiome from a couch potato, not a racer, if I would I be doing so well," Petersen told Bicycling magazine. "Then it made me wonder what the best possible microbiome for a racer would be."

So, how do you answer that question?

Petersen began testing the stool samples of both amateur and professional cyclists and was shocked to learn that there is a very real difference in the microorganisms living in the guts of the elites. Specifically, she found a microorganism — Prevotella — common among elite racers.

"The more a person trains, the more likely they are to have Prevotella," Petersen noted. "In my sampling, only half of cyclists have Prevotella, but top racers always have it ... it’s not even in 10% of non-athletes." There was Prevotella in the transplant that Petersen received. Another microorganism, Methanobrevibacter smithii, or M. smithii also was common in elite racers but was generally absent in the guts of amateurs.

Petersen says it's impossible to draw any direct connections between her experience with a rogue fecal transplant and what athletes can achieve by changing the microbes in their guts. But she is hoping that her research will lead to a better understanding of the microorganisms that we all have living inside our bodies and the adjustments that can be made in our guts to improve health and athletic performance.

"If you get tested and you’re missing something, maybe in three years you’ll be able to get it through a pill instead of a fecal transplant," said Petersen. "I think I can say with confidence that bacterial doping — call it poop doping, if you must — is coming soon."

Why 'poop doping' could be the next big performance-enhancer
A better understanding of what's going on in your gut could help make you a stronger athlete.