Similar genetic causes seem to cause both, research shows.
Type-1 diabetes and gluten intolerance, also known as celiac disease, share at least some genetic roots, researches have reported.
These findings may lead to new treatments for such auto-immune diseases, which are caused when the body's immune system mistakenly destroys healthy tissue.
The results of the study, published in the New England Journal of Medicine, also point to some of the same environmental triggers causing both conditions.
"These findings suggest common mechanisms causing both gluten intolerance and type-1 diabetes. We did not expect to see this very high degree of shared genetic risk factors," David van Heel of St. Barts Hospital and The London School of Medicine and Dentistry said.
The international team studied 9 339 healthy people, 8 064 people with type-1 diabetes and 2 560 people with gluten intolerance.
They found four gluten intolerance genetic mutations that also appeared often in people with type-1 diabetes and two diabetes mutations that also appeared to raise the risk of gluten intolerance.
Type-1 diabetes, also known as juvenile diabetes, is caused by the destruction of beta cells of the pancreas that produce the insulin necessary to regulate blood sugar levels. It is different from the far more common type-2 diabetes, strongly linked with poor diet and a lack of exercise.
Celiac disease, also an auto-immune disorder, attacks the small intestine and makes patients intolerant of gluten, a protein found in wheat, barley and rye. Symptoms include bloating, abdominal pain, nausea, skin problems, depression, joint or bone pain and nerve problems.
"The next step is to understand how these susceptibility genes affect the immune system, and to keep exploring environmental factors that might alter the risk of type-1 diabetes, which results from an incredibly complex interaction between nature and nurture," said John Todd of Britain's University of Cambridge.
According to the World Health Organization, at least 171 million people worldwide suffer from diabetes, with about 5 to 10 percent of them having type-1.
Celiac disease is estimated to affect about 1 percent of people of European descent. Do your children complain of bloating or nausea after meals? What do you give them to make them feel better?