AFAIK the gut in large terrestrial vertebrates has its own nervous system that rivals the complexity of the entire system in simpler creatures.

The idea that all stateful/regulatory stuff is entirely localised to the brain is a bit too simple to be true. Most of it, sure, but that last few percent can be doing all sorts of clinically important stuff. Nature is an incredibly brilliant engineer, but not always a tidy one.

I actually believe you... I was sure I can taste certain spicy things on their way out if you know what I mean :-D