Probiotics, Prebiotics and Mental Health

Growing older is associated with alterations in the gut microbiota and a reduction in mental capacity. Psychobiotics are microbiota-targeted treatments that can improve mental health and slow down the brain's aging process. In comparison to people who are neurologically healthy, Aljumaah et al. (2022) examined the gut microbiome composition and predicted microbial functional pathways of middle-aged and older adults who met the criteria for mild cognitive impairment (MCI), in addition to conducting a placebo-controlled, double-blind, randomized clinical trial to examine the effects of probiotic Lactobacillus rhamnosus GG (LGG). A total of 169 middle-aged (52–59 years) and older (60–75 years) community-dwelling adults were randomly assigned to probiotic and placebo groups for a three-month intervention. Samples were taken at baseline and after supplementation. Based on their cognitive condition, participants were subsequently separated into intact or impaired cognition groups. Prevotella ruminicola, Bacteroides thetaiotaomicron, and Bacteroides xylanisolvens were found to be taxa linked with MCI by microbiome study. Prevotella was found to be substantially more common in MCI participants than in cognitively intact subjects, according to differential abundance analysis at baseline. An increase in the MCI group's cognitive score was associated with a relative abundance decline of the genera Prevotella and Dehalobacterium in response to LGG administration. According to these results, the authors comment that some gut microbiota members are associated with middle-aged and older persons' cognitive function. Upon further confirmation, these taxa may be utilized as important early markers of MCI and may be stimulated by prebiotics, probiotics, and symbiotics to facilitate favorable brain aging outcomes.