title: Psychobiotics: a novel class of psychotropic.
abstract: Here, we define a psychobiotic as a live organism that, when ingested in adequate amounts, produces a health benefit in patients suffering from psychiatric illness. As a class of probiotic, these bacteria are capable of producing and delivering neuroactive substances such as gamma-aminobutyric acid and serotonin, which act on the brain-gut axis. Preclinical evaluation in rodents suggests that certain psychobiotics possess antidepressant or anxiolytic activity. Effects may be mediated via the vagus nerve, spinal cord, or neuroendocrine systems. So far, psychobiotics have been most extensively studied in a liaison psychiatric setting in patients with irritable bowel syndrome, where positive benefits have been reported for a number of organisms including Bifidobacterium infantis. Evidence is emerging of benefits in alleviating symptoms of depression and in chronic fatigue syndrome. Such benefits may be related to the anti-inflammatory actions of certain psychobiotics and a capacity to reduce hypothalamic-pituitary-adrenal axis activity. Results from large scale placebo-controlled studies are awaited.
authors.affiliation: Alimentary Pharmabiotic Centre, University College Cork and Teagasc Moorepark, Cork, Ireland. Electronic address: t.dinan@ucc.ie.
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Dinan
authors.forename: Catherine
authors.initials: C
authors.lastname: Stanton
authors.forename: John F
authors.initials: JF
authors.lastname: Cryan
mesh_terms: D000818:Animals; D003863:Depression / Q000628:therapy*; D041981:Gastrointestinal Tract / Q000382:microbiology / Q000502:physiology; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D064307:Microbiota; D010913:Pituitary-Adrenal System / Q000502:physiology; D019936:Probiotics / Q000627:therapeutic use*
keywords: Brain-gut axis; depression; microbiota; probiotics; psychobiotics; stress