BackgroundChronic constipation and depression are highly prevalent worldwide. These two conditions frequently co-occur in clinical practice. Accumulating evidence indicates that gut microbiota dysbiosis mediates this comorbidity through the microbiota-gut-brain axis (MGBA).MethodsThis narrative review systematically summarizes current research on MGBA bidirectional communication mechanisms, gut microbiota alterations in comorbid patients, and microbiota-targeted intervention strategies.ResultsTh