Prenatal depression is a prevalent complication during pregnancy that not only adversely affects maternal mental health and elevates the risk of postpartum depression but also has enduring implications for offspring development. Alterations in the host metabolome and gut microbiome have been linked to the onset and progression of depression; however, the biological mechanisms underlying the association between maternal mood disorders and fetal brain development remain inadequately understood. Recent studies have associated prenatal depression and psychological stress with alterations in the maternal gut microbiota, microbial metabolism, and immune signaling. However, most human evidence remains observational, and it remains unclear whether these microbial alterations precede depressive symptoms, arise as a consequence of depression or psychological stress, or act as intermediate factors within the maternal gut-brain axis. These findings offer novel strategies for the prevention and treatment of threats to maternal-fetal health. This article systematically reviews recent advancements in research concerning the "microbiota-gut-brain" axis in the context of maternal-fetal health. It investigates the roles and mechanisms of gut microbiota through preclinical and clinical studies, assesses the feasibility of potential therapeutic strategies, and suggests directions for future research. The aim is to provide a theoretical foundation for interventions targeting maternal-fetal health in cases of prenatal depression.
