NCT03664531

Dietary Triggers of Gastrointestinal Symptoms in IBS Patients

Crossover Trial of Purified Gluten and Whole Wheat (Gluten With Amylase-trypsin Inhibitors) as Triggers of Gastrointestinal Symptoms in Patients With Irritable Bowel Syndrome

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 29 (actual)
• Sponsor: McMaster University · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

This crossover randomized controlled trial will evaluate the effects of purified gluten and whole wheat (gluten combined with amylase-trypsin inhibitors (ATIs)) on inducing intestinal and extra-intestinal symptoms in irritable bowel syndrome (IBS) patients. All participants will be put on a gluten-free diet and then challenged with muesli bars containing either purified gluten, whole wheat (gluten with ATIs), or gluten-free sham.

Detailed description

Irritable bowel syndrome (IBS) is a heterogenous, common gastrointestinal disorder characterized by chronic abdominal pain and altered bowel habits. Many IBS patients report symptom relief on a gluten-free diet (GFD), but it is uncertain whether gluten is the true culprit. The gluten-containing grains wheat, rye, and barley all contain amylase-trypsin inhibitors (ATIs), and a GFD is virtually ATI-free. This double-blinded crossover randomized controlled trial aims to determine which IBS patients are affected by pure gluten and which are affected by gluten combined with ATIs. IBS patients who respond to and have been on a GFD for 3+ weeks will be randomized to receive a dietary challenge of muesli bars containing either 1) 10 g pure gluten, 2) whole wheat (containing 10 g gluten and wheat ATIs), 3) or gluten-free sham for a week followed by a 14 day washout. This will be repeated until all participants have had each dietary challenge. The study will evaluate the effects and potential mechanisms of purified gluten and whole wheat (containing the same dose of non-purified gluten) on intestinal and extra-intestinal symptoms in IBS. It is likely that some IBS patients respond to gluten, while others respond to whole wheat containing gluten combined with wheat ATIs. Thus, this project may lead to better diagnosis and individualized dietary treatments for IBS.

Conditions

• Irritable Bowel Syndrome

Interventions

Type	Name	Description
OTHER	Purified gluten	1 low FODMAPs, vegan muesli bar containing purified gluten per day for 1 week, for a total of 10 g purified gluten per day.
OTHER	Non-purified gluten (containing ATIs)	1 low FODMAPs, vegan muesli bar containing whole wheat flour with non-purified gluten per day for 1 week, for a total of 10 g non-purified gluten per day.
OTHER	Sham	1 gluten-free, ATI-free, low FODMAPs, vegan muesli bar per day for 1 week. This is a sham because participants were blinded to the identity of this gluten-free control and randomly assigned to it.

Timeline

• Start date: 2019-01-01
• Primary completion: 2022-04-01
• Completion: 2023-06-20
• First posted: 2018-09-10
• Last updated: 2026-04-01
• Results posted: 2026-04-01

Locations

1 site across 1 country: Canada