Assessing the Tolerability of Oligosaccharide Supplementation in Patients With Crohn's Disease

The investigators hypothesize that a novel method for oligosaccharide supplementation, in the form of nutritional bars and/or muesli high in fructans and galacto-oligosaccharides (GOS), will be a safe and tolerable therapeutic intervention in patients with Crohn's disease (CD) in remission.

Subjects age \>/= 19 years with the diagnosis of CD for \>/= 6 months, currently in remission based on the Harvey-Bradshaw Index score (\</=4 points) and C-reactive protein (\<5 mg/L) will be recruited from two academic hospitals and affiliated gastroenterology outpatient clinics (St. Paul's Hospital, Vancouver, British Columbia, Canada; Alfred Hospital, Melbourne, Victoria, Australia).

The study is a randomized, double-blind, placebo-controlled trial that consist of a 2-week run-in period followed by a 4-week study period. Prior to study entry, a screening visit will be required for all potential participants. If a participant meets the inclusion criteria, they will be randomized to either a placebo (0.55 g total fructans/GOS), a moderate oligosaccharide group (3.25 g total fructans/GOS) or a high oligosaccharide group (5.43 g total fructans/GOS) through a computed-generated scheme within each respective center. During the run-in period, enrolled subjects will undergo the following: 1) Laboratory analyses (CBC, routine biochemistry, CRP and fecal calprotectin); 2) Stool collection for fecal calprotectin analysis; 3) tolerability assessment including overall gastrointestinal symptoms and specific symptoms (abdominal bloating, abdominal pain, gut rumbling, flatulence) utilizing a 100mm visual analogue scale (VAS, 0 = no symptoms; 100 = worst symptoms ever experienced); 4) fatigue assessment utilizing a multi-dimensional fatigue impact scale (FIS); 5) health-related quality of life (HRQOL) assessment utilizing the Short Form 36-Item Health Survey (SF-36) and 6) Mood assessment utilizing the Spielberger State-Trait Personality Inventory (STPI). Participants will also meet with a registered dietitian to quantify baseline oligosaccharide consumption by completing a prospective 5-day diet diary alongside a validated food frequency questionnaire (FFQ), the Monash University Comprehensive Nutritional Assessment Questionnaire (CNAQ) that assesses oligosaccharide intake in addition to the usual nutrients \[49\]. Once the initial dietary assessment is complete, participants will begin up-titration of their oligosaccharide supplementation in a step-wise fashion until they reach their required daily amounts defined by their treatment group allocation. Once this is achieved, they will enter the 4 weeks of treatment or at time of relapse. Participants will undergo re-assessment during the study period at 2 weeks (Visit #3), and at study completion (Visit #4).

If a participant undergoes a CD flare during the run-in period, they will be withdrawn from the study. The end point of the study will be at 4 weeks of treatment or at time of relapse.

Eligibility Criteria:
Inclusion Criteria:

* age \>/= 19 years
* diagnosed with CD for \>/= 6 months, currently in remission based on the Harvey-Bradshaw Index score (\</= 4 points) and C-reactive protein (\<5mg/L)

Exclusion Criteria:

* unable to provide informed consent;
* have significant hepatic, renal, endocrine, respiratory, neurological, or cardiovascular disease;
* confirmed diagnosis of celiac disease, or have suspected celiac disease and are following a gluten-free diet to manage symptoms with an elevated screening anti-tissue transglutaminase antibody test;
* significant complications of CD which includes a history of extensive colonic resection, including subtotal or total colectomy, history of \>/= 3 small bowel resections or received a diagnosis of short bowel syndrome, current ileostomy, colostomy or ileal-anal pouch, or a fixed symptomatic intestinal stenosis;
* antibiotic use in the 4 weeks prior to study start;
* use of any rectal preparations in the 2 weeks prior to study start;
* use of any non-steroidal anti-inflammatory drugs in the 2 weeks prior to study start;
* use of commercial probiotic supplements in the 4 weeks prior to study start
* change in CD therapy in the 4 weeks prior to study start (excluding steroid taper, however steroid dosing must be stable for 2 weeks prior to study start);
* recently been adhering to a novel dietary intervention for alternative health issues within the last 4 weeks prior to study start.