Can probiotics make you a better endurance athlete?

Interesting paper by the international society of sports nutrition.

Research suggests that probiotics can:

  • Increase the absorption of nutrients in your gut
  • Improve immune system functions
  • Improve gut-barrier function
  • Act as an anti-inflammatory
  • Improve overall health
    Probiotics can expedite muscle recovery during resistance training.


There doesn’t seem to be much that is actionable in that paper. I don’t think that buying random probiotics at the health food store will make you faster. The new thinking, AFAICT, on probiotics is that they are more like a targeted medicine rather than a general purpose vitamin. My understanding is that probiotics out of a bottle do not permanently colonize your gut. They do displace the bacteria you have now. This could be a good thing if you have diarrhea or some condition.

The better thing to do is change your microbiome by eating healthy food (particularly a wide variety of vegetables and whole grains that contain fiber). You also want to eliminate alcohol, preservatives, chemicals, sugar, fast food, PUFAs, etc. (Sounds pretty familiar, hug? - eat healthy and your microbiome gets healthier.)

Fermented “probiotic” foods seem to correlate with better health and usually contain lots of fiber.

Personally I think prebiotic supplements and foods might be a better approach for an athlete. Prebiotics are indigestible fibers that nourish our short chain fatty acid producing bacteria. My theory is that we are all trying to burn more fat during long endurance rides. If our gut is producing more short chain fatty acids (butyrate, acetate, propionate) then we can use them for fuel at sub threshold activity.

I’ve been doing deep dives on this stuff for about a year now. I’ve found no magic bullet. I have increased vegetable and whole grains in my diet and I have supplemented with prebiotic powders. I honestly think that I do have more endurance sub-threshold. I feel that I can ride for hours and feel pretty fresh in hour 3 or 4 of a ride. I don’t think that prebiotics though have improved my FTP.


One of the studies that shows that pro athletes have increased short chain fatty acid producing bacteria.

AFAIK, the only way to get bacteria to permanently colonize the gut is by fecal transplant. So, maybe someday one could get a bacterial transplant or implant of the right bacteria to make you a better athlete.

This kind of stuff though is at the infant stage of development. They have cured things like C-difficile with fecal transplants but there have also been deaths and severe side effects. I read about one woman who was thin before the transplant but then packed on like 50 pounds afterwards. It’s like she caught obesity from the transplant.

The encouraging thing is that someday they may be able to cure obesity once they understand these mechanisms.

IMO a paper by a society representing sports nutrition companies, describing the benefits of a sports nutrition supplement, is not worth the paper it is written on, regardless of results.

Wait for it to be corroborated by the greater scientific community…


probiotics products:

And what is the importance of intestinal bacterial flora: