What’s the connection between the gut and brain health?

Gut bacteria may influence our emotions and cognitive capabilities. For example, some bacteria make oxytocin, a hormone the body produces that encourages increased social behavior. Other bacteria make substances that cause symptoms of depression and anxiety. Still others make substances that help people to be calmer under stress. Gut bacteria also have been shown to influence people’s vulnerability to certain brain diseases, including Alzheimer’s disease, Parkinson’s disease, and autism. For example, a substance found in the brains of people with Parkinson’s disease (synuclein) is made by gut bacteria and can travel via nerves from the gut to the brain.