Schizophrenia and the gut–brain axis

• Several risk factors for the development of schizophrenia can be linked through a common pathway in the intestinal tract
• The microbiota composition may impact the gastrointestinal barrier, immune regulation, and metabolism seen in schizophrenia.
• A significant subgroup of patients may benefit from the initiation of a gluten and casein-free diet
• Antimicrobials and probiotics have therapeutic potential that will be elucidated by further research

Several risk factors for the development of schizophrenia can be linked through a common pathway in the intestinal tract. It is now increasingly recognized that bidirectional communication exists between the brain and the gut that uses neural, hormonal, and immunological routes. An increased incidence of gastrointestinal (GI) barrier dysfunction, food antigen sensitivity, inflammation, and the metabolic syndrome is seen in schizophrenia. These findings may be influenced by the composition of the gut microbiota. A significant subgroup of patients may benefit from the initiation of a gluten and casein-free diet. Antimicrobials and probiotics have therapeutic potential for reducing the metabolic dysfunction and immune dysregulation seen in patients with schizophrenia.