Microbiota e depressão: existe uma relação?

Abstract

This systematic review had as objective the investigation of the relationship between the gut microbiota and Major Depressive Disorder. The literature search was carried out on the Pubmed, Cochrane and Lilacs platforms, by joining the search terms “microbiota” and “depression” in order to identify clinical studies that researched the relationship between microbiota and depression. Ten articles were selected that met the inclusion criteria from a total of 41 articles originally present in the initial search. Articles that consisted of clinical trials who sought to investigate the results of the administration of probiotics containing certain bacteria species in patients with depression were reviewed. Genomic analysis trials that sought to establish correlations between specific bacteria and symptoms of depression were also reviewed. This review found that there is a strong relationship between probiotic consumption and symptoms of depression, with bacterias from the Firmicutes and Actinobacteria phylum having been the most used in probiotics in experiments that resulted in alleviation of depressive symptoms. There was also a decrease in certain metabolites and certain inflammation factors in the intervention groups that consumed capsules containing bacteria, as well as changes in the composition of the microbiota in patients with depression. There is clear evidence of a correlation between the composition of the microbiota and clinical cases of depression, as well as a correlation between consumption of probiotics and a decrease in depressive symptoms. However, broader research is needed to establish more accurately the specific species of bacteria that can alleviate or worsen symptoms of depression and by what biochemical mechanisms the gut microbiota interferes with mental health, as well as to answer if probiotics constitute a good complement in the treatment with antidepressants.