HP and Crohn disease: In order to compare zonulin levels in these cohorts to patients with a disease affecting the gastrointestinal mucosa, serum samples from IBD patients divided into active ulcerative colitis (UC A, n=14), active Crohn’s disease (CD A, n=13) and Crohn’s disease in remission (CD R, n=12) were further included as controls (metadata in Table 1).