Serotonin

Serotonin is a chemical your brain produces that acts as a messenger between nerve cells. It plays a major role in regulating mood, sleep, appetite, and digestion.

It’s often called the “feel-good chemical” — when your levels are balanced, you tend to feel calm, focused, and emotionally stable. When they’re low, it’s strongly linked to depression and anxiety.

The surprising part most people don’t know: about 90% of your body’s serotonin is made in your gut, not your brain. That’s the direct connection between the microbiome and mental health — a healthy gut supports healthy serotonin production, which affects how your child feels emotionally, not just physically.