>>13589633these two things are not mutually exclusive
having a clean environment will prevent disease because the human won't have anything to catch
there's a reason operating rooms are always cleaned thoroughly before and after surgery
having a strong immune system will allow your organism to deal with germ-caused diseases more efficiently when it does catch them from an unclean environments
this is literally like 5th grade biology stuff, kids learn this when they're 11-12 years old
i fucking hate stupid-ass retarded americans