The study found that a significant number of people who report adverse reactions to wheat – but who do not have coeliac disease – had biomarkers indicating intestinal damage and systemic immune activation.
It is the first time biomarkers pointing to causes of wheat sensitivity in people who are not coeliacs have been identified.
The team are now looking at ways to develop a blood test which could be used to diagnose non-coeliac wheat sensitive patients, author professor Armin Alaedini of Columbia University medical centre, New York revealed.
“Currently, the only way for the diagnosis of non-coeliac wheat sensitivity is through thorough clinical examination that would involve food restriction and food challenge,” he told FoodNavigator.
As the new study shows clear biological changes in affected patients which trigger certain biomarkers: “We are working on developing a blood test that can be used to accurately diagnose cases of non-coeliac wheat sensitivity.”
It is hoped new treatment strategies will also become available as more discoveries about the potential mechanisms involved are made, Alaedini added. This will be both a challenge and an opportunity for the food industry, he said.
“We are only beginning to understand this condition. Other than dietary restriction of the offending foods, there is no other treatment and no medication is available for non-coeliac wheat sensitivity,” he noted.
“A lot more people than just those with coeliac disease and wheat allergy may need to avert foods that contain wheat and related cereals.”
The study recruited 80 patients suffering from non-coeliac wheat sensitivity, who reported intestinal or extra intestinal symptoms after eating food containing glutens including wheat, rye and barley.
“Gastrointestinal symptoms, most commonly abdominal pain, diarrhoea, and bloating, as well as extra-intestinal symptoms, such as fatigue, anxiety, depressed mood, and cognitive difficulties are reported by these patients,” Alaedini explained.
Six intestinal biopsies and serum samples were taken from each participant while on a diet containing wheat, rye and barley, the team wrote in the journal Gut.
Participants reporting problems with wheat had significantly increased serum levels of soluble CD14 and lipopolysaccharide (LPS)-binding protein. These people had antibody reactions to bacterial LPS and the bacteria-related protein flagellin.
Significantly raised circulating levels of the fatty acid-binding protein 2 (FABP2) – a biomarker pointing to intestinal epithelial cell damage -- were also noted, which could explain immune responses to microbial products.
It was found the FABP2 levels became normal again in a subgroup of 20 study participants who excluded wheat and related cereals (barley and rye) from their diets for six months.
The researchers stressed that, though potential biomarkers were found, the study does not address mechanism or molecular triggers responsible for damaging the gut.
Beside working on the development of a blood test for wheat sensitivity diagnosis, the team is therefore planning a number of follow-up studies to test which wheat products might be causing the intestinal cell damage in wheat sensitive patients, Professor Alaedini told us.
“We don’t know how wheat-containing food might be causing the intestinal cell damage. In other words, the mechanism and trigger for the presumed intestinal damage in the affected individuals are not known. We are now working on this.”
In the paper, the team added: “Further research is needed to investigate the mechanism responsible for the intestinal damage and breach of the epithelial barrier, assess the potential use of the identified immune markers for the diagnosis of affected individuals and/or monitoring the response to specific treatment strategies, and examine potential therapies to counter epithelial cell damage and systemic immune activation in affected individuals.”
Published online ahead of print, doi: 10.1136/gutjnl-2016-311964
“Intestinal cell damage and systemic immune activation in individuals reporting sensitivity to wheat in the absence of coeliac disease”
Authors: Melanie Uhde, et al.