ABSTRACT
Major depressive disorder (MDD) is a type of mood disorder characterized by a significant and persistent group of depressive symptoms. Gut microbiota may play a critical role in the pathogenesis of MDD. It has been found that the gut microbiota composition of MDD patients is significantly different from that of healthy controls, and depression phenotype can be transferred to rodents by fecal microbiota transplantation. Nevertheless, the mechanism of gut microbiota dysbiosis contributing to depression is complicated, and it is currently accepted that the microbiota-gut-brain axis is a crucial part. A set of probiotics and prebiotics have been found to have antidepressant properties, and related microbial therapies are expected to become an important method for treating depression and other mental diseases in the future.