Gastrointestinal Microbiome and related metabolites in Depression and Antidepressants - a comprehensive review

Depression, a prevalent mood disorder, has emerged as a significant health concern in society. While the exact cause of depression remains incompletely understood, there is substantial evidence linking the gastrointestinal microbiome and its metabolites to this condition. Through combined multi-omics analysis, it has been observed that the composition of the gastrointestinal microbiome, including Firmicutes , Bacteroidetes , and Actinobacteria , undergoes significant alterations in depressed individuals. Moreover, the production of short-chain fatty acids, tryptophan, and bile acids by these gut microbes is also found to be modified in depression. Furthermore, studies have demonstrated that antidepressant medications exert their therapeutic effects by interacting with the gastrointestinal microbiome and their metabolites. This review provides an overview of the association between the gastrointestinal microbiome, related metabolites, and depression. It highlights the potential of these factors to serve as mechanisms of action for antidepressant medications. Additionally, the review summarizes the commonly used technical tools in depression research.