Advances in Gut Microbiome and Metabolomics Research in the Comorbidity of Inflammatory Bowel Disease and Depressive Disorder

Inflammatory bowel disease (IBD) is a chronic autoimmune disorder characterized by persistent inflammation of the gastrointestinal tract, with a substantial proportion of patients experiencing comorbid depressive disorders. This comorbidity profoundly affects patients' long-term prognosis and quality of life. Emerging evidence suggests that the interplay between IBD and depression may be mediated by disruptions in the gut microbiome and metabolome. Notably, alterations in gut microbial composition and metabolic profiles observed in both IBD and depression indicate potential shared pathophysiological mechanisms, which could inform novel therapeutic strategies. This review aims to summarize recent advances in gut microbiome and metabolomics research related to IBD comorbid with depression, highlighting their implications for disease management and treatment. First, we provide an overview of the epidemiological features of IBD comorbid with depressive disorder, as well as the underlying pathophysiological mechanisms that may contribute to their bidirectional relationship. Subsequently, we highlight key microbiome and metabolite alterations observed in comorbid patients, which may contribute to disease onset and progression. At last, we also discuss emerging microbiota- and metabolite-based therapeutic approaches that hold promise for improving both gastrointestinal and psychological outcomes. In conclusion, integrating microbiome and metabolomics perspectives provides novel insights into the shared pathophysiology of IBD and depressive disorders and may inform the development of more effective and personalized interventions.