Fig. 5: The urinary wheat peptidomes of patients with CeD are significantly more diverse than in healthy controls or patients with non-celiac gastrointestinal disorders.

a Clinical study design. Participants were recruited over approximately 2 years within the Celiac Disease Program at the Stanford Digestive Health Center. Participant characteristics are reported in Supplementary Tables 3 and 4. b Number of wheat peptides detected in pooled urine samples collected for 8 h subsequent to a dietary challenge with two bagels (~18 g gluten). Patients with CeD had substantially more wheat peptide sequences compared to healthy controls (p = 0.017) or patients with non-celiac gastrointestinal disorders (p = 0.017). c Number of unique wheat-derived peptide sequences with at least one T-cell epitope in patients with CeD compared to healthy controls (p = 0.019) and patients with non-celiac gastrointestinal disorders (p = 0.046). b, c Statistics were derived from n = 6 patients with celiac disease, n = 5 patients with non-celiac gastrointestinal disorders, and n = 8 healthy controls using a one-way Kruskal–Wallis ANOVA/Dunn’s multiple comparison test; horizontal bar represents the median. d Venn diagram comparing the unique peptide sequences detected in healthy controls, patients with CeD, and other GI patients. A full listing of peptide sequences is provided in Supplementary Dataset 7. e Schematic describing how the frequencies at which urinary wheat-derived peptides map to proteins in the wheat proteome were plotted as heatmaps. f–h Heatmap representation of detected peptide sequences in alpha/beta gliadin 2 (GDA2), γ-gliadin 2 (GDB2), and gamma-gliadin X (GDBX) demonstrates that while many peptides map to the same region of the wheat proteome, the urinary wheat peptidomes of patients with CeD also occupy distinct chemical space. Below the maps, the locations of CeD T-cell epitopes are highlighted in red, and the relative density of Gln and Pro is indicated in yellow. Heatmaps for other proteins in the wheat proteome are provided in Supplementary Fig. 10. In b–h, all samples were analyzed by LC–MS/MS in duplicate and the aggregated results are shown. Analyses of individual replicates are provided in Supplementary Fig. 11. Full details on LC–MS/MS identification of peptide sequences are provided in Supplementary Dataset 7. Source data are provided as a Source Data file.