One thing is clear, at the most basic level, research shows that the more active you are, the more diverse your microbiome will be. Scientists have discovered that the athlete’s microbiome isn’t just more diverse; it’s also functionally different from that of sedentary subjects, with specific bacterial strains that assist with cell and muscle turnover, tissue repair, and the ability to harness maximum energy from foods.
In one study, professional and amateur competitive cyclists who trained rigorously for 16 or more hours per week had a high percentage of Prevotella in their guts (around 12 percent, much higher than the 0.15 percent most people harbor), a genus that could help with amino acid synthesis for improved recovery. What’s more, the professional cyclists showed high levels of M. smithii, a strain of bacteria involved in methane metabolism that may make bacterial fermentation in the gut microbiome more efficient, leading to an increase in short-chain fatty acids, reduced recovery time, and improved race performance.
In another trial, researchers tested fecal samples of runners both before and after running the Boston Marathon and found that the post-race samples included particularly high amounts of a type of bacteria that break down lactic acid, which can lead to muscle soreness and fatigue. The scientists also compared the gut bacteria of ultramarathoners to those of elite rowers and found that the ultramarathoners harbored a species of bacteria that the rowers didn’t—one that helps break down carbohydrates and fiber, very important during a 100-mile race but perhaps not as crucial during rowing.
So, not only do athletes tend to have more diverse, specialized microbiomes than nonathletes, but the gut bacteria of elite athletes seem to be, in some sense, sport-specific! And if you think about it, the implications are astounding. Fast-forward a few years and we may be able to pick our probiotic supplements based on our favorite sporting activity, choosing strains that can most readily support and guide our bodies toward the finish line.