Here's an interesting article about the microbiome and how our ancestral micriobiome appeared to be much better suited to breaking down fiber. Of course the diets back then were much higher in fiber. I'm not saying this article gets everything right, but there's a super interesting implication at the end about how when the micriobiome isn't diverse enough and we don't eat enough fiber then our less diverse micriobiome starts to eat away at the protective mucus lining in the digestive tract. Food for thought!