Blog The evidence and rationale supporting our stool donor criteria (2022,

About your screening process. Why are you so sure that young athletes are the most important group? What indicators are there that this group should yield the best results? Typically, they eat an unhealthy diet because they need a gargantuan amount of calories that are difficult to get with the best diets… you may see many more actionable biomes from people who eat natural Whole Foods, rather than the junk that many athletes inhale after exhausting their calorie supplies thus forcing their body’s starvation response. People who do moderate exercise, eat well, and like quiet lives away from intense sports outcomes is likely a much better set of environmental factors. I hate to see you bark up the wrong tree, continually retreading the same ground that yields 1 in a million type results…
You posted your comment off-topic elsewhere on the forum, so I'll ask if you read this blog post.

Typically, they eat an unhealthy diet
I question this and want some evidence for this claim. It is not accurate from what I've seen. For example, I saw an interview with Tyson Gay where he commented on how unenjoyable his diet was due to how strict it was. But I do also recall Michael Phelps saying he eats whatever he wants, including pizza, and has an alcohol problem. I've also seen Usain Bolt commenting on eating chicken nuggets at the Olympics, but I don't think that's his regular diet. Certainly there is some variation there, and as noted in the blog, just because someone is a world-class athlete doesn't automatically qualify them.

continually retreading the same ground that yields 1 in a million type results
I don't understand this sentence, and my guess is that it stems from having not read the blog and not understanding our process. The million+ applicants are coming from organic social media videos. They're not targeting anyone in particular, other than "social media users". That is why so few of the applicants come close to qualifying -- because chronic disease and general poor health are epidemic. No one gets disqualified for "not being an athlete". We are not excluding non-athletes in any way. So the fact that we think top young athletes are the ideal target group is largely irrelevant.
An argument can be made that top athletes should be disqualified because the use of peds extremely common at those levels. Especially in track, football, MMA and boxing. Drug testing is mediocre and athletes get caught all the time. Its very well known. I’ve been involved in sports all my life and I've seen it first hand too. Hell, half of the players on my high school football and track team were on something. Just imagine how common it is in college and professionally. Potential donors would never be willing to report that on the questionnaire.
Do you have any citations to support PEDs being disqualifying for stool donation? I have had athletes report PED usage on the questionnaire, but there are probably some who don't report it. The screening process is designed to account for omissions, and I don't know of any evidence supporting such a stance of disqualifying all top athletes due to this, much less enough evidence to counter all the pro-athlete evidence in the blog.
I’m am not aware of any, this is actually a good example of something that has not been studied yet because of the nascency of microbiome research but is quite intuitive. If we know that PEDs, particularly steroids, can lead to testicular atrophy, and a significant decrease in natural testosterone production, and that the microbiome is strongly associated with our hormonal profiles then it makes sense that people with past PED use would have compromised gut microbiomes.
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Exogenous testosterone use eventually atrophies the testes because endogenous testosterone creation is no longer necessary -- I suppose analogous to how your leg muscles would eventually atrophy if you stopped walking. It may be true that the microbiome has a modulatory effect on endogenous hormonal activity, but that doesn't necessarily mean that exogenous testosterone would harm the microbiome.
More and more research is revealing that the microbiome is involved in numerous physiological processes. If chronic use of exogenous testosterone or other PEDs leads to testicular atrophy, then when someone discontinues their use of PEDs, it makes sense that they would experience symptoms of low testosterone, correct? If we know that low testosterone is associated with symptoms such as depression, low energy, erectile dysfunction, increased body fat composition, etc., and that a poor microbiome is associated with these symptoms, then wouldn’t it make sense that chronic PED use has a negative effect on the gut microbiota?
there is a known association between the Microbiome and our hormonal profile.

“The mutual interaction between sex steroids and the gut microbiota plays a prominent role in the development of metabolic diseases”