Gluten free diet may help in diarrhea linked to irritable bowel syndrome

Gluten free diet may help in diarrhea linked to irritable bowel syndrome

Gluten free diet may help in ameliorating the symptoms of irritable bowel syndrome associated diarrhea in HLA DQ2/8 gene positive patients

Health News Highlights of Nutrition Remarks (May 13, 2013) Print PDF of  Gluten free diet may help in diarrhea linked to irritable bowel syndrome

Written by Ajay Kumar, M.S., Health News Writer for Nutrition Remarks, Solon, OH, USA.

Reviewed by Dr. Michael Camilleri, M.D., Professor, Mayo Clinic, Rochester, Minnesota. USA.

Gluten is a protein found in several grains such as wheat, rye and barley; it is a significant source of protein in vegetarian diets and provides texture to the foods. However, for some individuals, eating gluten can cause serious allergic reactions.

The Gluten protein is mainly found in the endosperm of grain Kernel (seed)

The Gluten protein is mainly found in the endosperm of grain Kernel (seed)

Generally, gluten is avoided in the diets of wheat-sensitive patients, and patients diagnosed with celiac disease (an autoimmune intestinal disease). Gluten free diets are also suggested to prevent many other gastrointestinal ailments, including Irritable Bowel Syndrome (IBS); however, there is a dearth of scientific evidence supporting the positive effects of gluten-free diets in people suffering from IBS in clinical practice [1]. Studying the effects of gluten in IBS patients could be difficult as IBS patients may vary in their genetic constitution and can therefore respond differently to the same stimuli. For instance, Human Leukocyte Antigen (HLA) is a gene found in humans and plays a role in immune function. DQ2 and DQ8 are subtypes of HLA and their presence increases the risk of celiac disease [2]. HLA DQ2/8 gene is also present in asymptomatic (having no symptoms of disease) people and in symptomatic IBS patients without celiac disease and they may respond differently from the IBS patients who don’t have HLA DQ2/8 genes; for example, they may have faster small intestinal transit (movement of content through the intestines), slower colonic transit and increased intestinal permeability [3, 4].

In the United States, 10- 15% people are afflicted with IBS. IBS is characterized by altered bowel habits and abdominal discomfort. Clinical studies have shown the benefits of gluten free diets in celiac patients. However, the recommendation of gluten free diets in IBS cases has not been established in depth. A recent study published in the journal of Gastroenterology, by Dr. Michael Camilleri, M.D. and colleagues (Vazquez-Roque et al, 2013 [5]) reported that gluten free diets may reduce some of the IBS symptoms particularly the frequency of bowel movements.

In this randomized controlled study, 44 patients (22 HLA DQ2/8 gene positive and 22 HLA DQ2/8 negative) with IBS- related diarrhea were selected. Patients were divided into 2 groups (each groups had 11- HLA DQ2/8 positive, 11- HLA DQ2/8 negative) and were randomly assigned to gluten containing or gluten free diets for 4 weeks.  All meals were prepared by a specialized diet kitchen.

At the end of study, subjects on gluten containing diets had more bowel movements as compared to subjects on gluten free diets. The effects of the gluten-containing diet were greater in HLA DQ2/8 positive than HLA DQ2/8 negative patients. Similarly, small bowel permeability (a measure of the barrier of the lining of the small intestine) was less in subjects who were on gluten free diets, compared to diets including gluten. The positive effects of gluten free diets were more conspicuous in HLA DQ2/8 positive subjects as compared to HLA DQ2/8 negative subjects. However, another study where patients previously had a clinical response to gluten withdrawal, did not find any differences in clinical responses to gluten free diet between HLA DQ2/8 positive and negative IBS patients [6].

According to the authors of the study, the subjects were not selected on the basis of prior gluten sensitivity and the participants were randomly assigned to the gluten-free or gluten-containing diets; hence, these observations have the potential for generalization. Though, further comprehensive studies are required to understand the exact mechanisms and effects on other symptoms such as pain and bloating, this study from Dr. Michael Camilleri’s group highlight the potential importance of gluten-free diets in management of bowel disturbance in patients with diarrhea- predominant IBS.


1.         Verdu, E.F., Editorial: Can gluten contribute to irritable bowel syndrome? Am J Gastroenterol, 2011, 106,  516-8.

2.         Biagi, F., P.I. Bianchi, C. Vattiato, A. Marchese, et al., Influence of HLA-DQ2 and DQ8 on Severity in Celiac Disease. Journal of Clinical Gastroenterology, 2012, 46,  46-50.

3.         Vazquez-Roque, M.I., M. Camilleri, P. Carlson, S. McKinzie, et al., HLA-DQ genotype is associated with accelerated small bowel transit in patients with diarrhea-predominant irritable bowel syndrome. European Journal of Gastroenterology & Hepatology, 2011, 23,  481-487.

4.         Vazquez-Roque, M.I., M. Camilleri, T. Smyrk, J.A. Murray, et al., Association of HLA-DQ gene with bowel transit, barrier function, and inflammation in irritable bowel syndrome with diarrhea. American Journal of Physiology-Gastrointestinal and Liver Physiology, 2012, 303,  G1262-G1269.

5.         Vazquez-Roque, M.I., M. Camilleri, T. Smyrk, J.A. Murray, et al., A controlled trial of gluten-free diet in patients with irritable bowel syndrome-diarrhea: effects on bowel frequency and intestinal function. Gastroenterology, 2013, 144,  903-911 e3.

6.         Biesiekierski, J.R., E.D. Newnham, P.M. Irving, J.S. Barrett, et al., Gluten causes gastrointestinal symptoms in subjects without celiac disease: a double-blind randomized placebo-controlled trial. Am J Gastroenterol, 2011, 106,  508-14; quiz 515.