..." I can't imagine how gut bacteria affect moods"... But you can imagine looking at a picture and feeling hungry. In addition to our fast new electrical ner

..." I can't imagine how gut bacteria affect moods"... But you can imagine looking at a picture and feeling hungry. In addition to our fast new electrical nervous system for rapid response there is the older slower endocrine system from when we were just bags of chemicals coordinating with concentration gradients (still are, but were). visual -> brain -> signals gut -> gut makes molecules to get ready -> molecules detected report to brain -> you drool Moods depend on the chemical balance of small molecules bacteria eat sleep and poop small small molecules. To consider that after billions of years of coexisting we, both multi cell & single cell, have not adapted to responding each others's small molecules is unthinkable