Researchers have identified three fragments in gluten that appear to trigger a disorder in people who are allergic to the wheat protein.
The findings, published on Thursday in the journal Science Translational Medicine, may lead to a more targeted cure instead of what sufferers practice now - life-long abstinence from food containing gluten, such as cereal, pasta, cookies and beer.
"If you can (narrow down) the toxicity of an allergen to a few components, that enables you to make a highly targeted therapy in a way that you no longer need to target the whole immune system," said researcher Robert Anderson of The Walter and Eliza Hall Institute of Medical Research in Victoria, Australia.
For people with the allergy, gluten causes an overreaction in the immune system that damages the lining of the small intestine, leaving it unable to absorb vitamins, minerals and other nutrients from food.
The sufferer is subject to chronic fatigue and risks osteoporosis, infertility, miscarriage and even cancers of the digestive tract - symptoms of what is called celiac disease.
In the study, 244 people with celiac disease in Australia and Britain ate food with gluten over three days and researchers then analysed the immune cells in their blood samples.
While gluten has some 16,000 components, Anderson said only three were responsible for the allergy.
"To our surprise, the majority of the immune response to gluten can fall back to just three components of gluten. It means the immune response is highly focused on maybe some particular forbidden fragments of the gluten," he said by telephone.
Anderson and some colleagues had since gone on to design an injectable drug containing very small doses of each of the three components.
The idea is to expose the immune system to regular but very small doses of the offending allergens so that the body can gradually get used to them.