I read this take somewhere that we are basically a vessel for our microbiome / gut Flora. Our moods, what food we crave, how social we are might all be impacted by them, in which case they do have some sort of control over not just how we feel, but how we behave. For instance if you eat a lot of sugar, you will crave more sugar, and the argument would be that it's the bacteria that have developed in your gut that are causing you to crave that sugar because that is what they consume (vs the more human-focused evolutionary argument of "sugar was rare and so humans have evolved to crave as much of it as they can get").

Reality is probably a mix of both (ie we are a complex system with wants/needs influenced by both our own body and the Flora that live within it).