PSYCHOTROPIC PROPERTIES OF PROBIOTICS: A SYSTEMATIC REVIEW

Background: Even though psychological disorders can be treated with various methods, one of the emerging concepts is psychobiotics. Psychobiotics are the probiotics that have psychotropic properties in it, and these probiotics proved with the proper administration could provide physiological and psychological benefits to healthy individuals. In past years, many interventions have been conducted to identify these effects using human and animal samples. Thus, the objective of this review is to summarise current human studies conducted to investigate the effect of probiotics on psychological conditions Materials and Methods: A literature search was conducted using different databases includes Scopus, Pub Med, Web of Science, Science direct, and Google scholar referring to the past 15 years. 526 studies have been extracted and after removing duplicates and studies that do not meet the inclusion criteria, twenty-two studies were selected to document in the present review from 2004 to 2018. Result: Majority of these studies have revealed the effect of probiotics for improving the psychological disorders such as anxiety, stress, and depression with the significant difference between experiment and placebo groups. Thus, some studies showed no significant difference between groups. This may be due to different dosages, probiotic strains, intervention duration used in the studies. Conclusion: Daily probiotic supplementation can positively affect psychological conditions among different populations. Keywords: Anxiety, stress, probiotics, psychobiotics