The cause of inflammatory bowel disease (IBD) is currently unknown, although partly attributed to interactions among genetic risk polymorphisms, environmental factors, gut microbiome, and host immunity. Diet, particularly those with plant-based products, have been shown in prior research to improve gut microbial composition, which has been linked to different IBD-related outcomes. This study is interested in evaluating the impact of prebiotics on gut microbiome composition and gut health in patients with IBD.

Dietary composition will be assessed at baseline and over the course of 16 weeks. Participants will be randomized to either consume an 8-week course of prebiotic supplementation beginning at week 0 or week 8. Stool samples will be collected at weeks 0 and 8. The stool will be analyzed for cross-sectional and longitudinal fecal microbial changes associated with different prebiotic and diet consumption patterns in the context of heterogeneous disease characteristics.

Inclusion Criteria:

• Ages 18 to 85 years old
• History of biopsy-proven ulcerative colitis (UC)
• Active symptoms (SCCAI >2)
• Concomitant use of 5-aminosalicylates, immunomodulators, and corticosteroids will be permitted, although initiation or dose adjustment must not have occurred within 30 days prior to enrollment.
• Concomitant use of biologic therapy will be permitted, although initiation or dose adjustment must not have occurred within 60 days prior to enrollment.
• Prior probiotics or other dietary supplements use is permitted but will be asked to be discontinued during the course of the trial

Exclusion Criteria:

• Prior colectomy
• Hospitalization
• Urgent need for abdominal surgery
• Unstable major medical condition
• Active malignancy under treatment
• Active alcohol or non-cannabinoid substance abuse
• Pregnancy or lactation
• Concerns for non-compliance

The investigator and outcomes assessor will not be aware of participants' assignments.