[carapace]

I'm old enough to remember when this sort of thing was "woo-woo", so it's good to see it getting a grounding in solid scientific investigation. "Let your food be your medicine." and all that, eh?

Historically our microbiome and the external environment must have been in a kind of dialog: available food would be a pretty direct function of the local ecosystem, and our feces, which are something like 80% microorganisms, would of course be integrated back into the soil. (It's not really that surprising, from this POV, that our bellies would have brains.)