The gut is so complex like that. So much that is beyond just what we eat in the here and now... our state of mind, long term diet, past infections can do so much to our gut flora. I'm surprised that I've been able to have coffee again without the loose motions after years of struggling with it - but for how long I'm not sure! And I have no idea what changed
I'm not sure but I think we are the only ape that doesn't eat mould or mouldy food . It's why we don't have a blue food group. The only reason is that we are so good at finding food we don't need to eat mouldy stuff. We can digest it, we just don't have any appetite for it.
Off foods, such as dairy or meats are different and you shouldn't eat those.