Emory Health Sciences Mar 12 2026 With more than 100 million neurons in the digestive tract, the gut is commonly known as the "second brain" in numerous cultures, including ancient Greece, Japan, China and India, linking digestion with physical and mental well-being. Now, a new study from Emory University explains the gut-brain connection, indicating that live bacteria from the gut can directly enter the brain, with potential implications for neurological health. Published in  PLOS Biology  in