Abstract:Depression is a prevalent affective disorder exerting negative impacts on an individual’s emotional and cognitive functions and is commonly complicated with other diseases. As depression is affecting increasingly younger populations, it poses a serious challenge to the mental health initiatives in China. In recent years, the relationship between depressive symptoms and gut microbiota has garnered increasing attention, fueled by the deepening research on gut microbiota. Lactulose, a medication aimed at promoting gut health and known for its potential benefits on emotional and cognitive functions, has sparked interests regarding its clinical application in ameliorating depressive symptoms. This article reviews the clinical research findings on the efficacy of lactulose in alleviating depressive symptoms and outlines the potential mechanisms through which lactulose may mitigate these symptoms. Furthermore, this article offers a perspective on the mitigation of depressive symptoms through the gut-brain axis.