Identification of Gluten Sensitivity in Irritable Bowel Syndrome

University of Bari40 enrolled

Overview

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.

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

DIAGNOSTIC

Masking

DOUBLE

Enrollment

Conditions

Non-celiac Gluten Sensitivity

Interventions

diet containing glutenDIETARY_SUPPLEMENT

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

Diet containing placeboDIETARY_SUPPLEMENT

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

Eligibility

Sex: ALLMin age: 18 YearsMax age: 70 Years

Medical Language ↔ Plain English

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.

Outcomes

Primary Outcomes

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.

Time frame: 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.

Time frame: 3 weeks