A common, seemingly innocuous virus can trigger the immune response to gluten that leads to celiac disease, new research from U.S. and Canadian scientists suggests.

Reovirus infections, which usually cause mild gastrointestinal or respiratory symptoms in humans, can trigger an inflammatory immune response to gluten and become “a key initiating event for developing celiac,” according to the study published in the journal Science.

Celiac disease is an autoimmune disorder that affects an estimated 300,000 people in Canada, although many of them have not been officially diagnosed. The disease is caused by an improper immune response to gluten, a protein found in wheat, rye and barley, which damages the lining of the small intestine. There is no cure for celiac disease, but it can be managed with a gluten-free diet.

In the latest study, one common strain of a human reovirus triggered an inflammatory immune response in mice and caused the loss of “oral tolerance” to gluten.

The study also found that celiac disease patients had much higher levels of antibodies against reoviruses than people without the disease. Those with high levels of reovirus antibodies also had high levels of what’s known as IRF1 gene expression, which plays a key role in the loss of oral tolerance to gluten.

Valerie Abadie, a University of Montreal professor who co-authored the study, said the findings are “very important.”

“This study is going to open the door to new research aiming at deciphering why people develop celiac disease and whether we could actually treat children affected by the disease,” she told CTV News.

Reovirus infections that may trigger celiac disease are especially concerning among children, who have immature immune systems and are more susceptible to viral infections at a young age.

“For those genetically predisposed to celiac disease, the combination of an intestinal reovirus infection with the first exposure to gluten could create the right conditions for developing celiac,” the researchers said in a news release.

For young Kingston Martyn of Kelowna, B.C., it all started with a stomach bug that left him with intestinal problems. His mother, Candace Martyn, said she kept taking him back to pediatricians and telling them that something was not right, but they told her Kingston would “grow out of it.”

Within a year, Kingston was diagnosed with celiac disease. He’s now careful to eat only gluten-free foods and his mother carefully packs his school lunch every day.

Candace Martyn has long wondered if the stomach virus triggered her son’s now chronic illness.

“He is the only one, we have no one in our family or extended family that has celiac disease at all,” she told CTV News.

Before he was struck by the stomach bug, Kingston was “a perfectly healthy boy,” she said. “It seems strange, that was the only trauma that could have triggered his celiac disease.”

The latest research raises the possibility of developing a vaccine that prevents reovirus infections and possibly stopping celiac disease from developing in children. There are currently no human vaccines available against reoviruses.

The authors of the study say there may be other factors that boost the risk of celiac disease, including diet and different kinds of bacteria in the gut, but they are now zeroing in on the reovirus.

With a report from CTV’s medical affairs specialist Avis Favaro and producer Elizabeth St. Philip