Interesting! Speaking of GLP-1 there's been work done with one of the microbiome populations, Akkermansia mucosa that produces GLP-1 itself, causes another population to do the same via a metabolite and triggers enteric L1 cells to do the same (mechanism unknown). All in that (free!) podcast I mentioned the other day.
Besides being dose dependent ( more food=more GLP-1) it also improves glucose control (might be the GLP-1 doing that).
Interesting that there's glucose control *before* weight loss.