New Study Finds That Gluten May Not Be the Culprit in IBS Symptoms

Irritable bowel syndrome (IBS) is a common disorder that affects the large intestine and causes signs and symptoms such as cramping, abdominal pain, bloating, gas, diarrhea or constipation, or both. 

IBS is a common condition. It affects about twice as many women as men and is most often found in people younger than 45 years. The exact cause of IBS is unknown. 

Symptoms of IBS can be triggered by food and stress. The role of food allergy or intolerance in IBS isn’t fully understood. But many people have worse symptoms when they eat or drink certain foods or beverages. Stress on the other hand causes the symptoms to worsen, and while it may aggravate symptoms, it doesn’t cause them.

Symptomatic treatment of IBS includes dietary adaptation, with a focus on prebiotics, probiotics, gluten, and fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs). FODMAPs are poorly absorbable carbohydrates that exert an osmotic load on the gut and are rapidly fermented by colonic bacteria, resulting in gas production causing abdominal distention, bloating, and pain. They are in many foods, including some vegetables and most legumes. 

New Study Findings 

A diet low in FODMAP has been shown to improve IBS symptoms and is currently the dietary factor with most evidence as a regimen for IBS. 

A new study published in The American Journal of Clinical Nutrition evaluating specific foods types and their effect on IBS. It was a double-blind, placebo-controlled, randomized 3-way crossover design in a clinical facility in Uppsala, Sweden. It included 110 patients with moderate to severe IBS diagnose.

Throughout the study, IBS participants maintained a diet with minimal FODMAP content and no gluten. They were block-randomly assigned to 1-week interventions with FODMAPs (50 g/d), gluten (17.3 g/d), or placebo, separated by a 1-week washout.   

They found that FODMAPs caused a higher IBS-severity scoring system (IBS-SSS) than those in the control groups or gluten, and no differences were found between the placebo and gluten groups. 

According to the results of this study, FODMAPs have a modest effect on typical IBS symptoms, whereas gluten had no effect. They concluded that dietary restriction of fermentable carbohydrates has a small, modest benefit on symptoms. 

They also found that all participants’ symptoms improved when they were on a combined low FODMAPs and low gluten diet. 


Elise Nordin, Carl Brunius, Rikard Landberg, Per M Hellström, Fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs), but not gluten, elicit modest symptoms of irritable bowel syndrome: a double-blind, placebo-controlled, randomized three-way crossover trial, The American Journal of Clinical Nutrition, 2021;, nqab337,

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