Dietary Therapies in Inflammatory Bowel Disease and Their Effects on Disease Activity and the Gut Microbiome

The rapid rise in inflammatory bowel disease (IBD) worldwide parallels urbanization and Westernization, including a shift towards the Western diet. This evolving epidemiological landscape shines a spotlight on the contributions of the environment to IBD pathogenesis and has generated particular interest in the role of diet as both a therapeutic and preventative strategy. Although epidemiologic studies have identified dietary risk associations and dietary intervention studies have demonstrated symptomatic benefit, the specific dietary components that influence disease course and the complex mechanistic pathways through which they act are incompletely understood. In this narrative review, we examine the clinical efficacy of dietary therapies studied in IBD and discuss their effects on gut microbial composition and function, recognizing the heterogeneity of evidence across dietary approaches and the evolving nature of this field. We also discuss emerging evidence linking diet, microbial metabolism and immune response, and consider how a better understanding of these interactions may inform future therapeutic strategies, optimize dietary interventions, and support the development of precision nutrition approaches in IBD. Overall, current evidence suggests that dietary therapies may benefit selected patients with IBD and are associated with changes in the gut microbiome, although their mechanisms and optimal clinical application require further study.