How Does Celiac Affect The Body? The villi along the walls of the intestines are like small fingers which aid the body in digesting food. In a person with celiac disease, the villi in the first few feet of the small intestine are shortened or completely flattened by foods containing gluten. Because the surface area of the intestinal wall is decreased, the body cannot absorb nutrients as efficiently. This lack of nutrients can cause a wide variety of symptoms, making celiac disease difficult to diagnose. Symptoms of Celiac Disease A variety of gastrointestinal and neurological symptoms can be caused by celiac, though some individuals may suffer from only nutrient deficiencies.