title: Early feeding, feeding tolerance, and lactase activity in preterm infants.
abstract: OBJECTIVE
  We sought to ascertain whether the timing of feeding initiation affected the development of intestinal lactase activity and whether there are clinical ramifications of lower lactase activity.
  
  
  METHODS
  Preterm infants (26 to 30 weeks' gestation; n = 135) were randomly assigned to begin enteral feedings at either 4 (early group) or 15 days of age (standard group). At 10, 28, and 50 days of age lactase activity was determined by measuring the urinary ratio of lactulose/lactose after the 2 sugars were administered.
  
  
  RESULTS
  Lactase activity increased significantly over time. Infants in the early group had greater lactase activity at 10 days of age (by 100%) and 28 days of age (by 60%) than the standard group. At 10 days of age lactase activity was greater in milk- versus formula-fed infants. The time required to achieve full enteral feedings, the number of abnormal abdominal x-ray examinations, and the total number of abdominal x-ray examinations were inversely related to lactase activity.
  
  
  CONCLUSIONS
  Early feeding increases intestinal lactase activity in preterm infants. Lactase activity is a marker of intestinal maturity and may influence clinical outcomes. Whether the effects of milk on lactase activity were due to the greater concentration of lactose in human milk compared with that in formula must be determined.
authors.affiliation: USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Shulman
authors.forename: R J
authors.initials: RJ
authors.lastname: Schanler
authors.forename: C
authors.initials: C
authors.lastname: Lau
authors.forename: M
authors.initials: M
authors.lastname: Heitkemper
authors.forename: C N
authors.initials: CN
authors.lastname: Ou
authors.forename: E O
authors.initials: EO
authors.lastname: Smith
mesh_terms: D000367:Age Factors; D004750:Enteral Nutrition; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000201:enzymology / Q000628:therapy*; D007413:Intestinal Mucosa / Q000201:enzymology*; D043322:Lactase; D007785:Lactose / Q000652:urine*; D007787:Lactose Intolerance / Q000201:enzymology; D007792:Lactulose / Q000652:urine; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D001616:beta-Galactosidase / Q000378:metabolism*
chemical_list: D007792:Lactulose; D043322:Lactase; D001616:beta-Galactosidase; D007785:Lactose