Your Gut Shapes Your Mind

The link between microbes and mood is rewriting mental health science, challenging decades of brain-only thinking. Three findings carry the story:

• Most of your serotonin is made in the gut, with bacteria helping build it.
• Bacterial transplants can move anxiety or calm between mice within days.
• The vagus nerve carries these signals before you ever feel them.

The next question is what happens when stress enters the picture.