Clinical Research Directory

Inclusion Criteria: * Known diagnosis of ulcerative colitis. * Measured fecal calprotectin of \>250 µg/g at screening. * Mild disease: Partial Mayo Scoring Index Assessment for UC between 0-4 (adult patients). * Mild disease: Pediatric UC Activity Index (PUCAI) between 0-34 (pediatric patients). * Tanner stage 5 for pediatric patients. * Weight \>50kg. * No changes to IBD-related medications in three months prior to study onset (stable therapy, including use of 5-aminosalicylic acid, biologics, and immunosuppressive medications; some minor adjustments allowed, such as increasing dose for weight change, or change to a compatible/generic treatment). * Men and women; the latter must be menstruating and using contraceptives. Exclusion Criteria: * Inability to provide informed consent. * Presence of Crohn disease, IBD unclassified, non-IBD bowel conditions (e.g., celiac), or motility disorder. * Use of systemic antibiotics for more than a week during two months prior to intervention, or any antibiotic use during the intervention. * Use of probiotic, prebiotic, or fibre supplements in month prior to intervention known to affect the gut microbiome (if these are present in foods, such as yogurt or fermented foods, this will be allowed). * Chronic use of laxatives or stool softeners. * History of abdominal surgery, including appendectomy. * Pregnancy or intention of the patient to become pregnant during the study period.