Whole-Food, Plant-Based Diet for Active Crohn's Disease

The purpose of this study is to assess the ability of a whole-food, plant-based (WFPB) diet to produce symptomatic remission in Crohn's Disease patients.

The goal of this proposal is to evaluate the efficacy of a whole-food, plant-based (WFPB) diet in the treatment of active Crohn's Disease (CD). Epidemiologic studies suggest that environmental factors, including diet, likely play a role in the pathogenesis and disease course of Inflammatory Bowel Disease (IBD). Evidence also exists to support the idea that dietary practices, such as adherence to a plant-based as opposed to a more "western" diet, can significantly modify the microbiome composition and intestinal barrier function - both of which likely impact the disease course of IBD. The overall hypothesis is that adoption of a WFPB diet will reduce both symptoms and intestinal inflammation in CD patients, as well as increase microbial diversity. Patients will be randomized to receive education on and adopt either WFPB or FODMAP diet, which will be adhered to for a total of 12 weeks. Two primary outcomes which will be assessed are rates of clinical remission based on sCDAI and also reduction in intestinal inflammatory burden based on fecal calprotectin. Several secondary outcomes will also be reviewed to include assessment for alterations in the gut microbiome and intestinal permeability, rates of clinical response based on sCDAI, changes in systemic inflammation based on CRP, and adherence rates to the diet interventions.

Eligibility Criteria:
Inclusion Criteria:

* 18 years or older.
* Have the capacity for informed consent.
* Subjects must carry a diagnosis of CD at time of enrollment; the CD diagnosis will be based on clinical impression and documentation of the treating physician.
* Have active symptoms based on sCDAI score of \> 175.
* Have active inflammation documented by either: a fecal calprotectin of \>150 µg/g; OR high sensitivity C-reactive protein (hs-CRP) \>5 mg/L; OR evidence of active inflammation on CT (Computer Tomography) or MR (Magnetic Resonance) enterography, based on discretion of reviewing radiologist; OR documentation of active Crohn's disease on colonoscopy, defined as SES-CD (Simple Endoscopic Score for Crohn's disease) score of 3 or greater.
* Patients may continue their currently prescribed, stable doses of medical therapy during the study duration.
* Ability to have no more than 2 drinks/day for men and 1 drink/day for women.
* Ability and willingness to adhere to one of the study diets.

Exclusion Criteria:

* Hospitalized patients.
* Disease activity score sCDAI \> 400
* Already following plant-based diet, FODMAP diet, or other nutritional trials.
* Have recent changes in medical therapy (no start or change in immunomodulator, natalizumab, or vedolizumab within 12 weeks; 5-ASA, anti-TNFα agent, ustekinumab, or tofacitinib within 8 weeks; or corticosteroids within 2 weeks of randomization).
* Have an ostomy or ileoanal pouch.
* Have known luminal stricture or stenosis that would preclude consumption of fresh fruits and vegetables.
* Plans for GI surgery within six weeks of enrollment.
* Pregnant, planning to become pregnant, or breastfeeding.
* Have other conditions such as diabetes or celiac disease that may impact ability to follow study diet.