Dietary Interventions and Oral Nutritional Supplementation in Inflammatory Bowel Disease: Current Evidence and Future Directions.

Background: Nutritional management has become an integral part of Inflammatory Bowel Disease (IBD) care, with growing evidence supporting specific dietary interventions alongside pharmacologic therapy. However, clinical guidance remains fragmented due to heterogeneous study designs and variable endpoints.

Objective: This review critically examines the current evidence on dietary strategies and oral nutritional supplementation (ONS) in both Crohn's Disease (CD) and Ulcerative Colitis (UC), highlighting their clinical applications, mechanisms of action, and limitations.

Methods: A comprehensive literature search was conducted using PubMed, Scopus, and Web of Science databases, analyzing studies on various dietary approaches and ONS in IBD.

Results: Exclusive Enteral Nutrition (EEN) is a first-line therapy in pediatric CD, while partial enteral nutrition (PEN) and the Crohn's Disease Exclusion Diet (CDED) show promising efficacy and better adherence in both children and adults. Whole-food-based interventions, including the Mediterranean Diet, Specific Carbohydrate Diet, plant-based diets, and emerging strategies such as CD-TREAT and the Tasty & Healthy diet, have demonstrated varying levels of benefit in disease maintenance and symptom control. Targeted exclusion diets-such as low-FODMAP, low-emulsifier, and low-sulfur diets-may relieve functional symptoms and influence inflammatory activity, although evidence remains preliminary. ONS plays a pivotal role in addressing malnutrition and improving outcomes in perioperative and hospitalized patients.

Conclusions: Dietary interventions and ONS represent valuable therapeutic tools in IBD management. Future research should prioritize standardized, well-powered clinical trials and personalized nutritional approaches to better define their role within integrated care pathways.