Elevated serum levels of a zonulin family protein (ZFP) are correlated with abnormal results of the Lactulose Mannitol test; the long-accepted standard for intestinal permeability (“leaky gut”). Elevated levels of ZFP have been associated with metabolic syndrome, obesity, and several autoimmune, inflammatory and neoplastic diseases. Such diseases include Celiac disease, type I diabetes, juvenile nonalcoholic fatty liver disease, and evidence is accumulating for multiple sclerosis, rheumatoid arthritis, asthma, and inflammatory bowel disease. The test may be used as a clinically equivalent alternative for those who don’t want to use the “sugar” load test.

α1-Antitrypsin is produced in the liver. It is not normally present in the intestines and, if so, only in very low concentrations. α1-Antitrypsin is an indicator of increased intestinal permeability and a marker of inflammatory activity in the intestine. can also be an indicator in Crohns disease.