The gut microbiota in post-stroke depression: A systematic review of microbial mechanisms and therapeutic targeting of neuroinflammation.

Post-stroke depression (PSD), a frequent and debilitating complication after stroke, severely hinders rehabilitation. Emerging evidence underscores the role of neuroinflammation and the gut microbiota in PSD pathogenesis. This review systematically elaborates the mechanisms by which gut dysbiosis contributes to PSD-related neuroinflammation via immune cell regulation (e.g., Treg/Th17 balance), microbial metabolites (e.g., SCFAs, tryptophan derivatives), and neural pathways (vagus nerve, HPA axis). A key focus is the comparative analysis of the gut microbiota in PSD against major depressive disorder (MDD) and Alzheimer's disease (AD), revealing a unique, stroke-induced microbial signature characterized by a loss of protective symbionts and a bloom of pro-inflammatory taxa. We further discuss the translational potential of microbiota-targeted interventions (e.g., probiotics, prebiotics) for PSD. By integrating clinical microbial ecology with mechanistic insights, this review synthesizes evidence suggesting that the gut microbiome may represent a promising diagnostic and therapeutic target for PSD, offering a distinct perspective from previous literature.