Identification of Gluten Sensitivity in Irritable Bowel Syndrome

Study Overview
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Brief Summary
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The aim of our study will be to establish in how many subjects with gastrointestinal symptoms and previous diagnosis of irritable bowel syndrome (IBS), the clinical picture is attributable to non celiac gluten sensitivity (NCGS) or fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) intolerance. For this purpose, all subjects with IBS will take a low FODMAPs diet, which implies the absence of cereals and consequently of gluten, and those presenting symptom improvement during this dietary treatment, will be exposed to a double-blind gluten or placebo challenge, to make a diagnosis of NCGS.

Detailed Description
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Study design: For this study, patients with diagnosis of IBS performed by Rome IV criteria and followed as outpatients at the Clinical Nutrition Clinic of Petrucciani Nursing Home of Lecce (LE), Italy, will be enrolled. At baseline, the enrolled subjects will follow a balanced normal-caloric low-FODMAP and gluten-free diet for a period of 4 weeks. At the end of the 4 weeks patients who did not experience an improvement in symptoms will be considered non-responders and discontinue the clinical trial. Only those subjects who had showed a significant improvement in symptoms, will be enrolled for the phase 2 of the study that includes a challenge with gluten or with placebo, as described by the Salerno criteria.

Official Title
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Double Blind Randomized Clinical Trial in Subjects With Irritable Bowel Syndrome for the Identification of Gluten Sensitivity

Conditions
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Non-celiac Gluten Sensitivity, Irritable Bowel Syndrome

Intervention / Treatment
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* Dietary Supplement: diet containing gluten
* Dietary Supplement: Diet containing placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: a gluten-containing diet for at least six months before enrollment anti-transglutaminase antibodies (IgA and IgG) absence normal serum IgA levels prick and specific IgE tests for wheat allergy negative Exclusion Criteria: celiac disease wheat allergy chronic intestinal inflammatory diseases psychiatric disorders major abdominal surgery (in particular intestinal resections) diabetes mellitus previous anaphylactic episodes gluten-free diet in the previous six months pregnant or lactating women.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Interventional study
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: patients with IBS treated with gluten<br>patients receiving gluten | Dietary Supplement: diet containing gluten<br>* gluten will be added for 7 days to the low FODMAP/gluten free diet diet. After 1 week of wash-out, patients will switch (cross-over) to placebo for another 7 days<br>|
| Placebo Comparator: patients with IBS treated with placebo<br>patients receiving placebo | Dietary Supplement: Diet containing placebo<br>* Placebo will be added for 7 days to the low FODMAP/gluten free diet diet. After 1 week of wash-out, patients will switch (cross-over) to gluten for another 7 days<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Identification of FODMAP intollerance in IBS subjects | To evaluate the FODMAP intolerance, the response to a low FODMAP diet will be assessed by a visual analogue scale (VAS) before and after the dietary challenge. The VAS scale consists in is a straight horizontal line of fixed length, usually 100 mm. The ends are defined as the extreme limits of the parameter to be measured (symptoms, pain, subjective feeling of well-being/malaise) orientated from the left (worst) to the right (best) The patient is invited to indicate a position (a point) along the line. | 4 weeks | 
| Identification of NCGS in IBS subjects who responded to low FODMAPs diet | To evaluate the NCGS, the response to the gluten challenge will be assessed by a visual analogue scale (VAS) before and after the dietary challenge. The VAS scale consists in is a straight horizontal line of fixed length, usually 100 mm. The ends are defined as the extreme limits of the parameter to be measured (symptoms, pain, subjective feeling of well-being/malaise) orientated from the left (worst) to the right (best) The patient is invited to indicate a position (a point) along the line. | 3 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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gluten free diet, FODMAPs, gastrointestinal symptoms