A common stomach bug that causes flu-like symptoms could be the missing link behind coeliac disease in children genetically predisposed to the affliction, according to an international study.  

The Norwegian researchers said an enterovirus infection may disrupt the gut microbiome and “trigger” the disease in infants born with the coeliac gene.

The highly contagious virus is common in children under three years of age, and may present as a runny nose, vomiting or breathing problems.

Coeliac disease, which causes an adverse reaction to gluten-containing foods such as bread and pasta, is one of the most common autoimmune diseases in Western countries.

In Australia, the condition affects approximately one in 100 Australians, but Coeliac Australia says this figure could be as high as 1 in 70 given the number of undiagnosed cases.

Almost all coeliacs are born with the HLA DQ2 or HLA DQ8 gene, but only around one in 40 of these individuals will go on to develop the disease.

Just why the disease occurs in some high-risk children and not others remains a mystery, prompting scientists to look more closely at possible environmental triggers.

For the study, published in The BMJ on Thursday, the researchers analysed the gut environment of 220 children (aged three months to three years) known to have the coeliac genes.

The researchers collected stool and blood samples and tested these for coeliac disease antibodies over time – with 73 children found to have at least one positive sample for enterovirus.

After an average of 10 years, 25 of the children would go on to receive a coeliac disease diagnosis.

One plausible explanation, the authors wrote, was that “enterovirus causes impaired barrier function, which in turn increases the risk of coeliac disease”.

In an accompanying editorial in BMJ, UK paediatricians suggested that young children with a “malabsorbing gut” could also be more vulnerable to a viral infection.

Coeliac expert Dr Jason Tye-Din told The New Daily that there is a body of evidence pointing to a “micro-organism” trigger, but those findings are still preliminary.

“There’s likely to be a range of bugs that could modify the environment of the gut in children who are predisposed to coeliac disease,” the Coeliac Australia medical chair said. 

“We need more compelling evidence to identify confidently the specific triggers and how they’re doing that.”

Dr Tye-Din said that while there’s a lot of interest in developing vaccines or probiotics to combat environmental factors, there is currently little that parents can do to reduce their children’s risk.

“Patients who have coeliac disease quite commonly ask me how they can prevent it happening in their child. There is a lot of interest but also anxiety,” he said.

“Clearly, the answer is that it’s partly genetic, but it’s not like you can always stop your child from catching a virus.”

Paediatric gastroenterologist at Murdoch Children’s Research Institute, Professor Katie Allen, said more research is required before clinical recommendations can be made.

“Further work is needed to show that the results are causative – not just associative – but nonetheless, it provides an interesting lead for trying to find the cause of coeliac disease which is a lifelong condition.”