The purpose of this study is to see how the prebiotic inulin changes the gut bacteria (microbiome) of children and young adults with IBD and determine if this dietary intervention can help reduce disease activity.

The pathogenesis of inflammatory bowel disease (IBD) is thought to be due to a combination of genetic, environmental and immunological factors. From a clinical stand point, there is great interest in determining if manipulation of the gut microbiota may be a viable therapeutic strategy in IBD patients. One such strategy involves the use of prebiotic. Prebiotics are oligosaccharides that cannot be enzymatically hydrolyzed in the small intestine, however serve as substrates for fermentation by commensal bacteria in the colon.

Investigators propose to evaluate the modulatory effects of the prebiotic inulin on the composition and function of the microbiota of children with IBD and determine the efficacy of this dietary intervention in reducing disease activity.

Inclusion Criteria

• Males or females age 8-21 years.

• Parental/guardian permission (informed consent) and child assent.

• Pediatric diagnosis of inflammatory colonic or ileocolonic Crohn's disease (CD), ulcerative colitis (UC) or inflammatory bowel disease-unclassified (IBDU), as defined by endoscopy, radiology, and clinical findings.

• Clinical disease activity index compatible with:

  • For patients with CD:

    • Pediatric Crohn's Disease Activity Index (PCDAI) ≤15 or short PCDAI (sPCDAI) ≤17.5 (if unable to complete full PCDAI) or physician global assessment (PGA) compatible with quiescent disease at time of enrollment
    • No visible blood in bowel movements in the 7 days prior to enrollment
    • Normal inflammatory laboratory markers (CRP, erythrocyte sedimentation rate (ESR), Albumin in the case of PCDAI)

  • For patients with UC/IBDU:

    • Pediatric Ulcerative Colitis Activity Index (PUCAI) ≤ 20 or PGA compatible with quiescent disease
    • No visible blood in bowel movements in the 7 days prior to enrollment

• Fecal calprotectin (FC) ≥ 50 ≤ 500mcg/g or FC outside of this range but within the 20% margin of error of 500 mcg/g

Exclusion Criteria

• Positive culture for an enteropathogen up to a month prior to enrollment or during the study period.
• PCDAI >15 or sPCDAI >17.5 for patients with CD or PUCAI >20 for patients with UC or IBDU
• Presence of an ostomy or prior colonic resection
• Short bowel syndrome
• Isolated perianal disease.
• Patients requiring escalation of treatment during the intervention or preceding enrollment, defined by the following: change in dose of azathioprine/methotrexate during the preceding 12 weeks or 5-amino salicylic acid during the preceding 2 weeks, change in dosing or interval of anti-tumor necrosis factor (TNF) therapy, or any other biologic therapy (ustekinumab, vedolizumab) for the preceding infusion or injection. De-escalation of therapy (i.e stopping a medication, or spacing the interval of medication or decreasing the dose of a medication) is acceptable.
• Use of oral steroids (with the exception of budesonide) within the last 4 weeks of the screening visit or during the study period.
• Use of any antibiotics during the preceding 4 weeks or during the study period.
• Use of commercially available prebiotic preparations during the preceding 3 weeks prior to starting the study drug or during the study period.
• Non-inflammatory Crohn's disease (stricturing and/or penetrating disease behavior)
• Isolated small bowel Crohn's disease
• Previous ileocecal resection