Because the body will recover when one goes gluten-free, the tests will then come up negative. Without a definitive test one may then stray from the diet, as one will feel well and was never sure that they had it in the first place. As for the two tests: The biopsy will look for flattened villi on the intestinal wall. After one goes gluten-free they will grow back. The blood antibodies are formed as a bodys reaction to the presence of the gluten. If no gluten, then no antibodies are present.