Gut microbiome plays a crucial role in the bi-directional communication between the gut and the brain. Recent research suggests that the gut microbiota can influence brain function via both the neuroimmune pathway and neuroendocrine pathways. Studies have shown that microbial diversity and taxonomic compositions were significantly changed in people with mood disorders as compared to healthy individuals. Most of the research studies revealed that short-chain fatty acids-producing bacterial genera were decreased, while pro-inflammatory genera and those involved in lipid metabolism were increased in patients with depressive episodes.