Temporary 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.

The Effect of Phototherapy on Intestinal Mucosal Enzyme Activity in the Gunn Rat

“…Diarrhea or green loose stools developing in jaundiced infants undergoing phototherapy have been described by several investigators (1,2,4,12,14). Bakken (1, 2) using lactose tolerance tests and histochemical staining for intestinal lactase described decreased activity in 6 jaundiced newborns undergoing photother apy.…”

“…Although reported side effects are few and relatively minor (12) general concern persists about the possible injurious effects of light on the human infant (3,14). While the occurrence of diarrhea in some infants under going phototherapy has been reported (2,14), and lactase deficiency has been suggested as the mechanism for the loose stools (1,2), others have denied these findings (27). In view of the controversy regarding the effect of light treat ment on neonatal stool patterns and the mecha nism of such an effect, we studied this problem using the congenitally jaundiced Gunn rat.…”

Phototherapy Increases Hemoglobin Degradation and Bilirubin Production in Preterm Infants

“…However, phototherapy is not risk-free, and there are few studies that address its complications and side effects. Adverse effects include increased insensible water loss, 14,15 electrolyte imbalance, 16 retinal and ocular injury, 35,36 increased gastrointestinal motility, 37,38 loss of nutrients and vitamins, 16,37,39 hypocalcemia, 40 changes in gonadotropin levels, 41 disturbance of blood flow, 42 DNA breaks, 43 cellular damage, 44 accidental hypoxia, 45 parental separation and anxiety, and parental infant behavior changes. 46 -48 Lipsitz et al 49 studied neonatal and infant mortality in relation to phototherapy and found that the number of infants with intracranial hemorrhage and/or pulmonary hemorrhage was higher in the phototherapy group than in the control group, although the difference was not statistically significant.…”

Effects of Jaundice and Phototherapy on Gastric Emptying in the Newborn

“…Diarrhoea occurs in about a quarter of all infants receiving phototherapy [10] and probably reflects inhibition of intestinal lac tase by bilirubin [11,12], which in turn shortens gut transit time [13]. This effect would not be expected to involve the stom ach, but jaundiced babies are commonly le thargic and feed poorly [4], and show func tional abnormalities of many different sys tems, e.g.…”