How do people get celiac disease?

Genetics; eat gluten: Celiac disease (gluten allergy) occurs in a person who may have a genetic tendency to react abnormally to gluten (a protein in wheat, barley, and rye). Something causes his immune system to over-react to gluten. Later, when he eats foods containing gluten, his immune system reacts with the intestine that is digesting the gluten, and causes intestinal damage, abnormal digestion, plus malabsorption.

Celiac Disease: It is an autoimmune disease mediated by the IgA antibody attacking cells that produce enzymes to help you break down wheat and gluten containing products.

Triggered event: Sometimes our immune system gets things wrong & this is one example. At some point, your immune system decides that one or more of the proteins in gluten are an enemy invader (like a virus).It develops antibodies to gluten that mistakenly attacks your intestinal tissue where gluten is absorbed.That injures the tissue.Any time you consume gluten, a new burst of antibodies form causing more injury