afaik
Well... it actually is a theory. Like, all modern dogs love to eat human shit, so there's been some evolutionary theories about how wolves/dogs of old have eaten human shit as an easy meal and thus part of their diets, and that might have aided in domestication and all that.
And now that I've already started to discuss dogs eating shit: My personal theory is, that rural dogs in India have human shit as a major source of their nutrition, since the sanitary conditions in many rural areas there are shitting in the bushes, and there's a lot of village dogs...
I wish I could eat like this - not only for the cost effectiveness, but it'd be better for the environment than meat! Having IBD really sucks. I can only imagine how difficult it is in the US where the medical care is so expensive on top of everything else.