Final answer:
Zonulin plays a critical role in celiac disease by increasing intestinal permeability, allowing gluten components to trigger an autoimmune response that damages the gut's villi, leading to malabsorption and health issues. Diagnosis is through serological tests and endoscopy, while treatment necessitates a gluten-free diet.
Step-by-step explanation:
The role of zonulin in celiac disease is significant as it regulates the permeability of the gut lining. In individuals with celiac disease, ingestion of gluten leads to the overproduction of zonulin, which in turn causes the tight junctions between the intestinal cells to become more permeable. This increased permeability allows for gliadin, a component of gluten, and other macromolecules to cross the gut barrier and enter the bloodstream, triggering an autoimmune response. The autoimmune attack inflames and flattens the villi of the small intestine, significantly hindering nutrient absorption, which can lead to malabsorption, malnutrition, and a variety of other health issues.
Diagnosis of celiac disease often involves serological tests to detect the presence of antibodies typical of the disease, followed by an endoscopy and biopsy to assess damage to the villi. Treatment for celiac disease currently requires a strict gluten-free diet, which alleviates symptoms and reduces the risk of long-term complications.