Gluten or wheat allergies may be psychological and linked to IBS

New research has uncovered that many people with irritable bowel syndrome (IBS) who believe they are sensitive to gluten or wheat may not actually have allergies to these ingredients.

Affecting an estimated 10% of Canadians, IBS is an intestinal disorder with one of the highest prevalence rates globally, according to the Canadian Digestive Health Foundation. Its underlying cause is unclear, and it can be disruptive and debilitating.

The McMaster University, US, study investigated participants with clinically diagnosed IBS who reportedly felt better eating gluten-free. They were fed cereal bars containing either gluten, whole wheat, or neither in a random order.

The researchers found that the number of people who experienced worse symptoms was similar across all three groups, including the gluten-free placebo. This suggests that expectations and beliefs, rather than gluten or wheat, may often be linked to perceived symptoms.

“Not every patient who believes they are reacting to gluten actually does. Some truly have a sensitivity to this food protein, but for many others, it’s the belief itself that’s driving their symptoms and subsequent choices to avoid gluten-containing foods,” says senior author Premysl Bercik, a professor with McMaster’s Department of Medicine.

Need for psychological evaluation

When the participants were informed which bars caused gastrointestinal symptoms, most did not change their beliefs or their diets. Bercik believes the findings suggest that some patients with IBS may benefit from psychological support and personalized care, apart from dietary guidance.

In one case example of this, the Cara Care app (recently acquired by Bayer) offers psychological and dietary support for IBS patients. This digital therapeutic combines evidence-based diet plans (like low-FODMAP) with cognitive behavioral therapy and hypnosis, letting users track symptoms, find triggers, get tailored meal plans, and develop coping strategies for the often-overlooked anxiety and depression linked to IBS.

“What we need to improve in our clinical management of these patients is to work with them further, not just tell them that gluten is not the trigger and move on,” Bercik urges. “Many of them may benefit from psychological support and guidance to help destigmatize gluten and wheat and reintroduce them safely in their diet.”

The researchers point to the psychological phenomenon known as the “nocebo effect,” where negative expectations alone can trigger real physical symptoms.The researchers point to the psychological phenomenon known as the “nocebo effect,” where negative expectations alone can trigger real physical symptoms, as part of the reason. Bercik says powerful social media influences and discussions in online communities can additionally fuel ideas around the harm that gluten causes.

“There is strong influence from the internet. Many patients post how bad they feel about gluten. Of course, it influences others,” he comments.

What lab tests revealed

He adds that for some people living with IBS, avoiding gluten is a way of taking control of their situation. “Continuing the gluten-free diet might provide patients with an actionable method to try to control their symptoms, although it means following unnecessary diet restrictions.”

The study was set up as a randomized, double-blind, sham-controlled crossover trial. Neither the 29 participants nor the researchers knew which bar was being consumed at any time. After each challenge, participants reported their symptoms, and stool samples were analyzed to objectively measure gluten intake.

While most participants reported they ate the gluten or wheat bars, lab tests revealed many did not. According to the study, only about a third actually followed the diet as instructed, suggesting some may have skipped the bars to avoid symptoms.

The study was published in The Lancet Gastroenterology and Hepatology, funded by the Canadian Digestive Health Foundation and the Society for the Study of Celiac Disease.

In other recent scientific investigations, dsm-firmenich found that a synbiotic capsule with microencapsulated sodium butyrate significantly eased IBS symptoms in adults in just four weeks. This marks the first time butyrate has been combined with a synbiotic for IBS, allowing for lower doses of other biotics and a convenient capsule form.

Meanwhile, an ex vivo study by Kaneka Probiotics and AB-Biotics revealed their probiotic blend, i3.1, can protect the intestinal barrier in IBS sufferers, addressing “leaky gut syndrome.” The research clarified the molecular mechanisms by which specific strains improve gut barrier function, restoring it to healthy levels quickly.