The Gut-Mood Link

Your gut bacteria also help shape your mood. They influence neurotransmitters, and gut cells generate most of the body's serotonin, a chemical tied to feelings of well-being. Signals travel both ways along the vagus nerve, so the state of your microbes can affect how you feel, think, and handle stress.

This is why disrupting the gut community with poor diet or repeated antibiotics can ripple far beyond digestion, touching everything from anxiety to sleep.