In the cross-sectional IBD cohort (Table 1, Fig. 3), several stool proteins (Haptoglobin, MMP-12, MPO, PGRP-S, Properdin, TIMP-1) significantly discriminate UC from HC with AUCs from 0.89–1.00 (p < 0.0001), compared to Calprotectin (AUC = 0.73; not significant). Here, PGLYRP1 is linked to irritable bowel syndrome.