The bioactive compounds of probiotic foods/supplements and their application in managing mental disorders

Background: Probiotics have recently become popular among all generations, ranging from children to the elderly. They are living microorganisms known to improve gut flora by establishing and maintaining gut health via molecular mechanisms that involve various bioactive compounds produced and released throughout the body, which may cause a bacteria-host interaction. These bioactive compounds of probiotics may be bacteria or other compounds that are associated with various neurotransmitters, which produce different actions on the body. Changes in gut microbiota composition have been associated with various diseases, including mental disorders such as Alzheimer’s/dementia, Parkinson’s, schizophrenia, stress, anxiety, and depression. Clinical reviews and studies on both animals and humans have given mixed results regarding the efficacy of probiotic foods and supplements in managing mental disorders. In our review, we advocate for probiotic foods to be functional foods, but we are unable to accept probiotics as an effective treatment for the management of mental disorders due to indeterminate evidence. Keywords: Probiotics, bioactive compounds, mental disorders, Alzheimer’s disease, dementia, Parkinson’s, schizophrenia, stress, anxiety, and depression