I understand that one of the important microbes for producing GLP-1 is Akkermansia Mucinophilia (sorry if I mangled that). There's been some IMO interesting work - and at least one company is capable of producing it in quantity (although it's quite labor intensive and so expensive).

Elsewhere I've seen that Akkermansia isn't present in the Hadza (one of the last true hunter-gatherer populations). The Hadza aren't starving, but they aren't in the presence of food abundance, so the lack of a GLP producing population probably doesn't matter, but I have to wonder where it came from. It's an anaerobe, doesn't survive in the presence of oxygen in any quantity. Maybe one of our food animals (the Hadza are not pastoralists)? Any thoughts?