PROBIOTICS : A Novel Class of Psychotropic
Timothy G. Dinanemail address, Catherine Stanton, John F. Cryan
Received 25 February 2013; received in revised form 12 April 2013; accepted 2 May 2013. published online 11 June 2013.
A psychobiotic is 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
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.
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.