I read an interview once with a guy who, due to various intolerances and circumstances, ended with a raw meat diet. He has some source of getting good meat, like a farm which also lets him take the animal straight to the butcher, stores it frozen, and eats it just like that, IIRC.

He said that in the beginning, he had trouble digesting it, until he let some meat get to borderline rotting and then ate that. Somehow that colonized his gut with a biome which could digest it, and he was golden after that.

Something to think about in this context...

Personally, I find most milk to be difficult to digest, but cheese and yogurt and such goes over quite well.

Edit: https://archive.is/cX98n https://www.vice.com/en/article/nnqw3q/this-guy-has-eaten-no...