Box 1.

Inclusion and exclusion criteria

Healthy Controls Inclusion Criteria: The Healthy controls enrolled were subjects of both sexes, aged ≥18 years, of Italian nationality, with no relatives with UC, and who did not present evidence of illness on the basis of the anamnestic data collected.

Patients with Inactive Disease Inclusion Criteria Patients with inactive disease were subjects of both sexes Inactive disease was assessed by clinical evaluation and endoscopy with biopsies Patients with a total Mayo score <3 or partial Mayo score <2, with Mayo endoscopic subscore of 0-1 and inactive histological disease (according to Robarts index), and with fecal calprotectin <250 µg/g.

Patients with Active Disease Inclusion Criteria Patients with active disease were subjects of both sexes Active disease was assessed by clinical evaluation and endoscopy with biopsies Patients with total Mayo score >10 or partial Mayo score >7, with Mayo endoscopic subscore of 3 and active histological disease (according to Robarts index), and with fecal calprotectin ≥250 µg/g.

UC Patients (Both Active and Inactive) Exclusion Criteria Under 18 years of age Pregnancy Prior proctocolectomy Presence of stoma Concomitant treatment with antibiotics, prebiotics, steroids, biological therapies, thiopurines or methotrexate, or anticoagulant drugs. Only treatment with mesalazine was allowed.