Psychological factors are supposed to play an important role through “brain-gut interactions” in functional gastrointestinal diseases (FGIDs) and irritable bowel syndrome (IBS) as well as inflammation bowel disease (IBD). Recently, scientists also found that anxiety and depression may be triggered by stress-induced changes to the gut bacteria. The gut-brain axis has been arisen as a major topic of interest in psychiatry. There is a common comorbidity of between psychiatric and gastrointestinal patients, and a large percentage FGIDs are more prevalent in the major depressive disorder (MDD) patients. Therefore, my editorial review for the journal will be focusing on the most prevalent research of the relative brain and gastroenterological investigations to enrich our current knowledge.