TITLE:
Gluten Restriction and Dietary Replacement in Adults without Gluten Related Disorders—A Critical Narrative Review
AUTHORS:
Noorah Saleh Al-Sowayan, Shumua Abdulaziza Alqayani, Bashayr Khalid Almatrudi, R.A.S. Alkhurayyif, Ghala Ibrahim Alfulayw
KEYWORDS:
Gluten-Free Diet, Low-Gluten Diet, Dietary Replacement, Gut Microbiome, Diet Quality, Cardiometabolic Health
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.17 No.11,
November
2,
2026
ABSTRACT: Objectives: To distinguish gluten-specific effects from dietary replacement effects in adults without gluten-related disorders. Background: Gluten restriction changes cereal sources, fermentable substrates, fortification, and processing, complicating interpretation of biological and clinical findings. Methods: This critical narrative synthesis expanded an initial reference set through targeted searches updated on 15 October 2026. Retrieved records, article text, and tables informed interpretation. Adult interventions, higher-risk populations, mixed-age context, cohorts, and product surveys were distinguished. Full-text access was incomplete for two reports (Campagna and Henriques), which were appraised from indexed abstracts and, where available, secondary extraction. No meta-analysis or formal certainty grading was performed. Results: Interventions show selected microbial changes without consistent clinical consequences. Product surveys frequently identify lower protein or micronutrient content, with category-specific exceptions. A randomized oat-versus-rice low-gluten trial demonstrates replacement-related differences without isolating gluten removal. Inflammatory, weight, and well-being findings remain mixed or imprecise. Cohorts do not establish cardiovascular benefit from restriction. Microbial and compositional differences alone do not establish disease risk. Conclusion: Evidence does not support routine restriction for general health improvement without a medical indication or establish universal harm from a nutritionally adequate gluten-free diet. Future trials should distinguish gluten from food substitution and connect mechanistic endpoints with clinical outcomes.