A Dietary Intervention Study on the Microbiome in Crohn's Disease Patients

Not Applicable

Completed

Brief Summary: This protocol is designed to compare the effectiveness of a soy-based diet or identical diet without soy given to patients with Crohn's disease (CD) in remission, patients with active CD, or healthy controls. The assigned diet will be compared to participant 'baseline' (pre-diet) in terms of its ability to change the gut bacteria and fecal butyrate, an important short-chain fatty acid (SCFA) that limits bowel inflammation, a characteristic of this debilitating disease.

Detailed Description: The inflammatory bowel disease (IBD) subtype, Crohn's disease (CD) is a chronic and relapsing inflammatory disorder of the gastrointestinal tract. Although the precise etiology of IBD is not known, evidence suggests that environmental factors, including diet, contribute to its pathogenesis. A soy-based diet has been demonstrated to have numerous health benefits. This single-center open-label study will compare the effectiveness of a soy-based diet or an identical diet without soy to change the gut microbiota composition and fecal butyrate concentration to that of baseline (pre-diet) in patients with CD (remission or active disease) and healthy control subjects without CD. Participants will follow either a soy-based diet or an identical diet without soy to which they will be randomized for 7 days. No data collection or other study procedures will take place until the potential participant provides written informed consent to participate in the research study. The informed consent, screening, enrollment, and baseline data collection which make up visit 1 can occur on the same day or be completed across several days.

Recruitment & Eligibility

Inclusion Criteria

CD subjects: Documented diagnosis of Crohn's disease. Control subjects: no documented diagnosis of CD.
CD subjects: Harvey Bradshaw Index (HBI) score <4 ('CD remission'), or with HBI score >8 ('CD moderate disease')
Capable of providing consent to participate
Access to technology that permits the daily completion of study related activities
Able to receive and have an adult sign for food shipments delivered to a work or home environment.
Negative pregnancy test at screening visit in females of childbearing potential
Able to take oral nutrition and medication intake for 3 months prior to and at time of study enrolment.
'CD remission' subjects: No change in 'IBD related' medications within 8 weeks prior to normally scheduled appointment with treating gastroenterologist (pre-screening): biologics, immunosuppressants, corticosteroids.

Exclusion Criteria

Short bowel syndrome.
Hospitalized patients
Body mass Index <19 kg/m or ≥35.
Known clinically significant liver/gallbladder/pancreatic disease/dysfunction
Individuals who lack consent capacity, including the mentally ill, prisoners, cognitively impaired participants, dementia patients.
Uncontrolled Diabetes Type I type II
Known drug abuse.
Known parasitic disease of the digestive system. symptomatic intestinal stricture.
Presence of an ostomy.
Known concurrent malignancy.
Other conditions that would be a contraindication to and of the study diets (e.g. Soy, peanut, wheat, gluten allergy.) or preclude the participant from completing the study
Start of new 'IBD related' medications within 8 weeks prior to enrollment: biologics, immunosuppressants, corticosteroids.
Documented C difficile colitis within four weeks of screening
Well-founded doubt about the patient's cooperation.
Existing pregnancy or lactation.
Current participation in another diet intervention, simultaneous participation in another clinical trial, or participation in any other dietary intervention trial within the last 30 days.
History of <3 natural bowel movements per week.
Unable to access to technology that permits the daily completion of study related activities.
Currently consuming a soy-based diet

Arm && Interventions

Group	Intervention	Description
Soy-based diet	Soy based diet	Participants will be randomized to follow a soy-based diet for 7 days. The diet will be preceded by a 12-hr overnight fast.
Regular diet	Non-soy based diet	Participants will be randomized to follow a diet without soy for 7 days. The diet will be preceded by a 12-hr overnight fast.

Primary Outcome Measures

Name	Time	Method
Maintenance of Symptomatic Remission, Without Worsening of Any Existing Disease Activity During Study Period	7 days	The primary aim will measure the Crohn's Disease Activity Index (CDAI) at the enrollment and end of study visit. CDAI scores can range from 0 to \~600 (A score of less than 150 corresponds to relative disease quiescence (remission); 150 to 219, mildly active disease; 220 to 450, moderately active disease; and greater than 450, severe disease). Herein, a cut-off value of \<150 was selected so that most patients below this threshold would be rated by physicians as 'very well'. Change was calculated from two time points as the value at the later time point minus the value at the earlier time point \[i.e., value at 7 days (post) minus value at baseline/enrollment (pre)\].
Change in Fecal Myleoperoxidase (MPO) Activity	7 days	Change in fecal myleoperoxidase (MPO) activity at day 7 vs day 0.

Secondary Outcome Measures

Name	Time	Method
Changes to Functional Composition of Gut Microbiota	measured after the 7-day diet intervention	Secondary outcome will focus on changes to the functional composition of fecal gut microbiota, including bacterial butryate production after the diet intervention.
Percentage of Subjects Who Continue Diet Following Completion of Study	6 months	To assess the percentage of patients who intend to continue the study diets when prepared food is no longer provided without cost, and the reasons for discontinuation of either diet (compared to resuming usual food habits).