The current state of research for psychobiotics use in the management of psychiatric disorders–A systematic literature review

Abstract

The need to find new therapeutic interventions in patients diagnosed with psychiatric disorders is supported by the data suggesting high rates of relapse, chronic evolution, therapeutic resistance, or lack of adherence and disability. The use of pre-, pro-, or synbiotics as add-ons in the therapeutic management of psychiatric disorders has been explored as a new way to augment the efficacy of psychotropics and to improve the chances for these patients to reach response or remission. This systematic literature review focused on the efficacy and tolerability of psychobiotics in the main categories of psychiatric disorders and it has been conducted through the most important electronic databases and clinical trial registers, using the PRISMA 2020 guidelines. The quality of primary and secondary reports was assessed using the criteria identified by the Academy of Nutrition and Diabetics. Forty-three sources, mostly of moderate and high quality, were reviewed in detail, and data regarding the efficacy and tolerability of psychobiotics was assessed. Studies exploring the effects of psychobiotics in mood disorders, anxiety disorders, schizophrenia spectrum disorders, substance use disorders, eating disorders, attention deficit hyperactivity disorder (ADHD), neurocognitive disorders, and autism spectrum disorders (ASD) were included. The overall tolerability of the interventions assessed was good, but the evidence to support their efficacy in specific psychiatric disorders was mixed. There have been identified data in favor of probiotics for patients with mood disorders, ADHD, and ASD, and also for the association of probiotics and selenium or synbiotics in patients with neurocognitive disorders. In several domains, the research is still in an early phase of development, e.g., in substance use disorders (only three preclinical studies being found) or eating disorders (one review was identified). Although no well-defined clinical recommendation could yet be formulated for a specific product in patients with psychiatric disorders, there is encouraging evidence to support further research, especially if focused on the identification of specific sub-populations that may benefit from this intervention. Several limitations regarding the research in this field should be addressed, i.e., the majority of the finalized trials are of short duration, there is an inherent heterogeneity of the psychiatric disorders, and the diversity of the explored Philae prevents the generalizability of the results from clinical studies.

Association between gut microbiota and anxiety disorders: a bidirectional two-sample Mendelian randomization study

“…No literature evidence has been found linking Selenomonadales to AD. However, it may be related to major depressive disorder (MDD) and Alzheimer's disease [38,39] . In previous studies on anxiety disorder cases, it has been found that individuals with AD have lower levels of Coprococcus [40] .…”

Effectiveness of Psychobiotics in the Treatment of Psychiatric and Cognitive Disorders: A Systematic Review of Randomized Clinical Trials

“…These findings advocate for a personalized approach in psychobiotic administration and emphasize the necessity for targeted research to optimize these interventions, considering the heterogeneity in patient responses and specific biochemical pathways affected by different probiotic strains. Future research should focus on standardizing psychobiotic formulations and exploring their synergistic effects with conventional antidepressants to fully harness their therapeutic potential [14,24,96].…”

Human Gut Microbiota for Diagnosis and Treatment of Depression

“…The results of these studies are detailed in articles focusing on specific probiotics, as well as in systematic reviews and meta-analyses [ 43 , 76 , 133 , 134 , 135 , 136 , 137 , 138 , 139 ]. This concept has given rise to the term ‘psychobiotics’, which encompasses probiotics, prebiotics and all microbiota-targeted interventions that positively impact mental health [ 138 , 140 , 141 , 142 ]. The majority of these studies primarily utilized various strains of lactobacilli and bifidobacteria as potential antidepressant probiotics.…”