Can gut bacteria influence mental health? There is a medical revolution underway with the potential to treat a range of behavioural and mood disorders, including autism, ADHD, MS and Alzheimer's disease. A growing number of scientists now believe that it is important not to ignore digestive issues because they see the gut as our second brain. The program explores the intricate relationship the gut microbiome has with the brain, and how early exposure to antibiotics, and consumption of the wrong foods, can throw this dangerously out of balance.