RecruitingDietary supplementSingle-cell Immune Response to Controlled Gluten Ingestion in Pediatric Celiac DiseaseThis study investigates how the immune system of children with celiac disease responds to controlled, small amounts of gluten. Children on a strict gluten-free diet are randomly assigned to receive either placebo, 50 mg of gluten, or 5 g of gluten once daily for three days, simulating real-life accidental exposure or dietary transgression. Blood samples are collected on Day 1 (before gluten intake) and Day 8 (five days after the last dose). Stool and urine samples are also collected for complementary analyses. Using single-cell ribonucleic acid (RNA) sequencing, T-cell receptor sequencing, microRNA profiling, and exploratory metabolomics, the study aims to characterize changes in immune cell populations and gene expression after gluten exposure. The objective is to determine whether even very small amounts of gluten induce measurable systemic immune responses and whether these responses differ according to the dose administered. Understanding these mechanisms may support the development of new biomarkers and improve clinical management of pediatric celiac disease.