title: Temproary intestinal lactase deficiency in light-treated jaundiced infants.
abstract: The intestinal lactase activity in six newborn jaundiced light-treated infants with diarrhea and in eight normal controls were compared by lactose tolerance test (LTT). The ability to hydrolyze lactose was minimal in the jaundiced infants during light-treatment compared to the controls which could absorb lactose very well. Peroral intestinal biopsies were taken from the newborn jaundiced infants during light-treatment. By histochemical technique no intestinal lactase activity was found in these intestines. When the jaundiced infants with diarrhea were given lactose-free diet, the stools normalized. The effect was reversed when breast milk was given while the baby was still jaundiced and light-treated. These findings indicate that the increased amounts of unconjugated bilirubin in the intestine of jaundiced infants during light-treatment inhibit the intestinal brush-border lactase. When the icterus fades the lactase is again active. The practical consequence is to give light-treated infants lactose-free diet if they get diarrhea, and to reintroduce breast milk or other lactose containing diet when the baby is no longer icteric.
mesh_terms: D001663:Bilirubin / Q000378:metabolism; D003967:Diarrhea / Q000201:enzymology; D004032:Diet; D006801:Humans; D007231:Infant, Newborn; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000201:enzymology / Q000473:pathology; D007567:Jaundice, Neonatal / Q000201:enzymology / Q000628:therapy*; D007785:Lactose / Q000378:metabolism; D007787:Lactose Intolerance / Q000178:diet therapy / Q000209:etiology*; D007789:Lactose Tolerance Test; D008027:Light / Q000009:adverse effects*; D010789:Phototherapy
chemical_list: D007785:Lactose; D001663:Bilirubin