Source of human intestinal tissue
Human intestinal tissue was obtained from 16 children (median age: 4 months) undergoing clinically indicated resection of the small or large intestine (tissue donor information in Table S1). Patients with systemic inflammatory disorders, metabolic disorders, or systemic immunosuppression were excluded. The use of human tissue for research was approved by the SickKids Research Ethics Board (REB #1000059282). All experiments were carried out in accordance with The Code of Ethics of the World Medical Association (Declaration of Helsinki) for experiments involving human subjects. Privacy rights of all human subjects were observed, and informed consent was obtained from the parents/guardians.