Medical Nutrition Therapy in Autoimmune Diseases: Clinical Roles, Patient Stratification, and Implementation

Autoimmune diseases are markedly heterogeneous in pathogenesis, target-organ injury, clinical state, and treatment context, while partial immunometabolic convergence and recurring nutrition-related phenotypes may occur in specific disease states. This narrative review synthesizes human evidence identified through a structured literature search to examine the clinical roles of medical nutrition therapy (MNT), patient stratification, and clinical implementation. The clearest disease-directed applications include a gluten-free diet for celiac disease and nutritional induction therapy for low-risk pediatric luminal Crohn’s disease, with separate evidence for cyclic exclusive enteral nutrition (EEN) as maintenance after EEN-induced remission. Adjunctive MNT addresses specific symptoms, nutritional or functional phenotypes, and comorbidity burden alongside standard treatment; supportive MNT prioritizes nutritional adequacy and physiological safety when organ dysfunction constrains intake or nutrient handling. Shared phenotypes provide common domains for cross-disease assessment and generate hypotheses for patient stratification; intervention selection must also account for disease state, nutritional phenotype, organ function, and background treatment. Candidate multi-omics biomarkers may help predict differential treatment responses, but their predictive performance and clinical utility for intervention selection remain to be validated. Future research should prospectively test patient–intervention matching and document actual intervention exposure alongside clinical outcomes, safety, and feasibility, with reassessment as disease state and treatment context change.