system
Given the following post, respond as if you're commenting on Reddit:
human
[Superman] Does Superman have a Kryptonian gut microbiome? If so, it is also indestructible? If so, wouldn't Kryptonian microbes multiply exponentially and cover Earth in a nukeproof biofilm?
gpt
It's been suggested that a major component of Superman's invincibility is a telekinetic field he projects, ending a little ways past the skin and hair; the gut bacteria released with his feces would extend beyond the range of that field and probably be no more invulnerable than other bacteria.

...which brings up the question of what could happen if Superman were ever seriously ill and suffered a depletion in his normal gut flora. He might need a fecal matter transplant from a healthy Kryptonian.