The community of microorganisms that live inside of your stomach is one of the most important markers of health, physically and psychologically.
Neuroscientists now think of the gut as a "second brain"; it independently controls your digestive processes and is in constant conversation with your main brain. What do they talk about? Depression, theorizes Dr Emeran Mayer.
We all feel things in our gut – intuitions that give us subtle physiological alerts, stress and anxiety that unsettle us, bad reactions to food, and conversely feelings of contentment from the right food, or flutters from an exciting experience. But according to Dr Emeran Mayer, what we feel is just a small fraction of what’s going on in a region of our body that is still quite mysterious – even to the experts.