TREH and nutritional deficiency disease: We have previously reported reduced gene expression of a range of digestive enzymes including enterokinase, aminopeptidases A and N, two trypsinogens, diprolyl peptidase 4, folate hydrolase, angiotensin converting enzyme, alkaline phosphatase, maltase-glucoamylase, sucrose-isomaltase, lactase, and trehalase in children with malnutrition and environmental enteropathy (50).