The short-chain fatty acid butyrate is a byproduct of gut microbe digestion of plant foods. It is associated with decreased systemic inflammation, insulin sensitivity, benefits in mood and cognition, etc. You can see in this diagram it increases GLP-1 and 5-HT (serotonin). Might some people benefit as much from whole, plant foods as they do from liraglutide or sertraline?
Butyrate
herbivores.life 