Efficacy and safety of probiotics in the treatment of depression and anxiety: An umbrella review of systematic reviews of randomized clinical trials

Background

Depression and anxiety have several consequences on human health and are the most prevalent mental disorders in the world. The central nervous system is known to be affected by the gut microbiota. Therefore, the consumption of probiotics can act as an alternative for the treatment of these disorders.

Objectives

This umbrella review aimed to evaluate the effects of probiotic in patients diagnosed with depression and anxiety through an overview of systematic reviews of randomized clinical trials.

Methods

Systematic searches were conducted in PubMed, Scopus, and Web of Science databases until May 2023. This review was registered at PROSPERO (CRD42021246244). Efficacy and safety were assessed based on the results of depression and anxiety scale scores, and the adverse events reported. The quality of the studies and the certainty of the evidence was assessed using AMSTAR 2 and GRADE pro tools respectively.

Results

Twenty-one systematic reviews were included. Some studies showed promising results for the use of probiotics in depression treatment. However, the AMSTAR 2 tool revealed that ten studies (47.6%) were rated as "Moderate," four studies (19.0.%) as "Low," and seven studies (33.4%) as "Critically Low" in terms of methodological quality. Regarding adverse events, only 5 studies report it. Based on the GRADE pro evaluation the force of recommendation probiotics for depression and anxiety is still strength remains weak.

Conclusion

More systematic reviews with higher-quality, following meticulously recommended methodological guidelines should be conducted to assess the efficacy and safety of probiotics as intervention in patients diagnosed with depression and anxiety.