PT  - JOURNAL ARTICLE
AU  - L T Weaver
AU  - M F Laker
AU  - R Nelson
TI  - Neonatal intestinal lactase activity.
AID  - 10.1136/adc.61.9.896
DP  - 1986 Sep 01
TA  - Archives of Disease in Childhood
PG  - 896--899
VI  - 61
IP  - 9
4099  - http://adc.bmj.com/content/61/9/896.short
4100  - http://adc.bmj.com/content/61/9/896.full
SO  - Arch Dis Child1986 Sep 01; 61
AB  - The sequential changes in intestinal lactase activity of 40 neonates were measured indirectly from the differential uptake and excretion of lactose and the non-metabolisable disaccharide lactulose contained in formula feeds. A daily decline in urinary lactose:lactulose excretion ratios, reflecting a rise in intestinal lactase activity, followed formula feeding. Percentage decline was related directly to gestation: full term infants displayed a fivefold greater decline in lactosuria than infants with a gestation of 28 weeks during the first 10 days of milk feeding. The difference between lactose:lactulose ingestion and excretion ratios suggests that within five days of starting feeds intestinal hydrolysis of lactose exceeds 98% efficiency, even in very preterm infants.