This study will assess the effect of gluten on gut barrier function. Investigators at the Mayo Clinic have developed a new gut permeability test using rhamnose (sugar & water solution), and are hoping to prove its effectiveness in a clinical setting.

The aim of this study is to assess effect of gluten on the gut barrier function in patients at high risk for celiac disease and non-celiac gluten sensitivity (NCGS) patients. This study will assess the gut permeability in three groups of patients 1) children who are at high risk for developing celiac disease (CD) (siblings of patients with celiac disease), 2) Children who are self-diagnosed with NCGS and 3) control group of patients matched for age and gender. Patients will undergo celiac serologic and genetic testing, after which the rhamnose test will be performed to assess the presence of increased gut permeability.

High Risk group:

• Sibling with a confirmed diagnosis of celiac disease
• No history Celiac disease or any other bowel disease

Non-Celiac Gluten Sensitivity group:

• Self-diagnosis of gluten sensitivity
• No history of celiac disease or other bowel disease

Healthy group:

• Absence of celiac disease or any other bowel disease
• No sensitivity to gluten

The study population will consist of three groups of children, aged 2-17 years. The first group will be children with siblings that have celiac disease, the second group will be children with non-celiac gluten sensitivity and the third group will be healthy children.