Gluten doesn’t impact IBS symptoms, researchers find

Gluten and fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) have less effect than expected on irritable bowel syndrome (IBS), according to a new study.

The focus of this research, published in the American Journal of Clinical Nutrition, was to give participants a high intake of a wide range of FODMAPs, gluten, or placebo, and to evaluate the effects on IBS symptoms.

Researchers from Chalmers University of Technology and Uppsala University in Sweden served different varieties of rice pudding to 110 participants living with IBS. One type of rice pudding was made with high levels of gluten, the other contained large amounts of fermentable carbohydrates with certain chains of fructose and lactose. In addition, the researchers also served a neutral rice pudding that served as a placebo.

Participants ate each variety of rice pudding in random order, for one week per category. The subjects' gastrointestinal systems were given high doses (1.5 times daily intake in a normal population) of FODMAPs or gluten. The findings showed that while the FODMAPs aggravated the symptoms, it was not to the extent that the researchers had expected based on results from previous studies. Gluten, however, was found to have no measurable negative effect on the subjects' perceived symptoms.

“Diet studies are difficult to conduct double blind, as it can often be obvious to the participants what they are eating,” said Elise Nordin, lead author of the study and PhD student in Food Science at Chalmers. “This is a big obstacle, as knowledge that something has been added to or removed from the diet can affect the result. The fact that we succeeded in creating diets that were completely blind, together with the large number of participants, makes our study unique.”