Gluten irritation is in the mind, not gut, for some IBS sufferers

Thousands of people who suffer from irritable bowel syndrome swear off a range of food categories to improve their symptoms. One of these categories is gluten, although a new small study shows it might not be the villain many think it is.

Irritable bowel syndrome (IBS) is a condition in which people can experience a range of gastrointestinal upset including pain, constipation, bloating, diarrhea, excessive gas, and more. Oftentimes, IBS patients will cycle through all of these symptoms at different times.

The condition afflicts between 25 and 45 million in the US alone and, according to the International Foundation for Gastrointestinal Disorders, many people have to wait an average of 6.6 years for their symptoms to receive an IBS diagnosis. During that time, many individuals will naturally turn to their diets to try and sort out what might be causing them so much discomfort and for some, dietary tweaks are indeed sufficient to lead to improvement.

But, as doctors begin to understand the condition better, it's looking like IBS has a strong psychological component. The current thinking is that there is something wrong with the brain-gut communication pathways and that physical symptoms one person might feel in their digestive tracts feels much more severe or urgent to those suffering from IBS.

A new small and simple study from Canada's McMaster University fits within this view of the disease as one that might have a stronger brain-oriented cause than one that is found in the gut.

Researchers there gave 28 individuals who believed that they were sensitive to gluten or wheat a range of cereal bars that contained either gluten, whole wheat or neither. The study was conducted in a double-blind manner so that neither the researchers nor the participants knew which bar was which. Instead, to find out which bar had been consumed, the team analyzed the feces of the participants for confirmation.

After each participant ate the bars for a period of 7 days, there was a "washout" period of 14 days, and then they were given the next bar to eat for another 7 days. After receiving self-reported symptom reports from each participant, the researchers found no statistical difference regardless of the bars being consumed – 93% of the patients reported adverse effects after eating each bar whether or not it contained gluten or wheat.

“Not every patient who believes they are reacting to gluten actually does," says senior study author Premysl Bercik, a professor with McMaster’s Department of Medicine. "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.”

Bercik says that online IBS forums might be perpetuating the belief that gluten is bad for those with the condition.

“There is strong influence from the internet," he said. "Many patients post how bad they feel about gluten. Of course, it influences others. Continuing the gluten-free diet might provide patients with an actionable method to try to control their symptoms, although it means to follow unnecessary diet restrictions.”

The researchers feel they witnessed a phenomenon known as the "nocebo effect" in which the presence of negative expectations is enough to trigger physical symptoms. They also say that in addition to removing potentially unnecessary diet restrictions for IBS patients, their work should encourage doctors to look at the condition from a whole-body perspective.

“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 concludes. "Many of them may benefit from psychological support and guidance to help destigmatize gluten and wheat and reintroduce them safely in their diet.”

The study has been published in The Lancet.

Source: McMaster University