Fecal Microbiota Transplantation(FMT) - reconstitution of normal flora by a stool transplant from a healthy individual, is increasingly being recognized as a therapeutic modality for diseases that are associated with gut dysbiosis.

This is a placebo-controlled, double blinded interventional study evaluating multiple, oral, fecal microbiota transplantation, administered in newly diagnosed pediatric patients with mild-moderate UC.

The primary objective is to assess the safety and feasibility of multiple, oral, fecal microbiota transplantation, in newly diagnosed pediatric patients with mild-moderate UC.

All processing will occur at the Center for Microbiome Research at Assaf Harofeh Medical Center, under GMP conditions.

Inclusion Criteria:

• Patients newly diagnosed (>9 months) with mild to moderate ulcerative colitis as per colonic biopsy and clinical disease activity (SCCAI 5-12).
• Patients not started on immune-suppressive or anti-inflammatory medications (Mesalamine is allowed).
• Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately. Women of childbearing potential will have a urine pregnancy test, which must be negative, on Study Day 1, prior to receiving FMT. Men treated or enrolled on this protocol must also agree to use adequate contraception prior to the study and for 3 months after FMT.
• Ability to understand and the willingness to sign a written document, including the willingness to accept risk of unrelated donor stool.
• Ability of parents or other legal guardian to understand and the willingness to sign a written informed consent document, including the willingness to accept risk of unrelated donor stool.
• Ability to swallow oral medications.

Exclusion Criteria:

• Severe, uncontrolled ulcerative colitis.
• At time of enrollment, immune-suppressive or anti-inflammatory medications, except Mesalamine.
• Patients with active or uncontrolled bacterial, viral, or fungal infection(s) requiring systemic therapy.
• Delayed gastric emptying syndrome
• Known chronic aspiration
• Patients with a history of significant allergy to foods not excluded from the donor diet (excluded foods are tree nuts, peanuts, shellfish, eggs)
• Pregnant and breast-feeding women
• Participants who are unable to swallow pills.

The placebo capsules are blocked capsules containing a mixture of saline and glycerine, identical in appearance and consistency to the FMT capsules.