In recent years， the presence of gut microflora dysbiosis among mood disorder patients has attracted more and more attention. The gut microbiota communicates with the central nervous system via the microbiota-gut-brain （MGB） axis to achieve two-way regulation， which affects people's cognition， emotion and behavior. Probiotics and their products can reshape the intestinal microecology， improve the function of immune and endocrine systems， and restore the level of neurotransmitters. Therefore， the application of probiotics to regulate the imbalance of gut microbiota and restore the disorder of MGB axis is becoming an adjuvant therapy for mood disorders. However， there are still some problems in probiotic therapy， such as the heterogeneous nature of both the gut microbiota composition and probiotics strains. In the future， more trials are urgently needed to determine specific probiotics strains for different subtypes of mood disorders to improve the treatment strategy.