You mean it’s so hard to find the mythical perfect [Human Microbiota] donor. They don’t exist because we don’t know what that looks like on a detailed level. Everyone has pathogenic microbes. They are necessary because it’s the COMMUNITY that matters, not the individual members. Every healthy community, from microbes to men, needs the superstars and the assholes to work together towards a greater goal.
-Reid Kimball, in response to an online discussion where someone commented that their potential donor had h.pylori and it was impossible to find a “perfect” donor.