“A bunch of elite cyclists have a microbiome that looks like this,” the way Petersen describes, fecal transplant expert and professor Elizabeth Hohmann from Massachusetts General Hospital told Gizmodo. “So what? Is that because of the foods they eat?” After all, it could be the lifestyle that makes their microbiome look the way it does, not the microbiome that makes them better performers. “There are associations, but not causal. The idea that [microorganisms like] Methanobrevibacter smithii or Prevotella will make you a better performer is ridiculous.”and this
And the fact that Petersen felt better after a fecal transplant is an anecdote that could simply be the placebo effect in action.
There’s always the chance that poop doping could be harmful, too. “There’s the risk of transmission of infections agents for sure,”and more definitely worth a read.