DISACCHARIDE DIGESTION AND MALDIGESTION

All food carbohydrates are hydrolysed to monosaccharides before transp ort across the microvillus membrane. The digestion of disaccharides an d some oligosaccharides is undertaken by a number of small intestinal brush border enzymes: sucrase-isomaltase, lactase phlorizinhydrolase, maltase-glycoamylase and trehalase. The distribution of the enzymes in the small intestine has been investigated. Different disaccharide mal digestion syndromes have been described. Lactase deficiency in adults is a condition found in the majority of inhabitants of the world. Howe ver, the prevalence varies widely between different populations. Sucra se-isomaltase deficiency is a very rare congenital condition except in Greenland. Trehalose maldigestion is likewise rare outside Greenland. Different hypotheses regarding the molecular background of the maldig estion syndromes are discussed.