Lactase-Treated Feeds

Enhanced weight gain in preterm infants receiving lactase-treated feeds: A randomized, double-blind, controlled trial. Erasmus HD, Ludwig-Auser HM, Paterson PG, et al. J Pediatr 2002;141:532-7.

Objective: To evaluate whether lactase-treated preterm feeds enhance weight gain and feeding tolerance in premature infants.

Study design: Prospective, double-blind, randomized, controlled trial involving 130 infants (26-34 weeks postconceptual age). The primary outcome variable was weight gain (g per day). Other outcome measures included gains in length and head circumference, biochemical indexes of nutritional status, feeding intolerance, and incidence of necrotizing enterocolitis.

Results: On study day 10, weight gain (mean ± SEM) of the treatment group was significantly greater (P < .05) than that of the control group (20.4 ± 1.8 g/day vs 15.5 ± 1.6 g/day). By study end, no significant difference in weight gain between treatment and control groups was observed. The difference in serum albumin level was significant at study day 14, with a value of 29.3 ± 0.6 g/L in the treatment group compared with 27.1 ± 0.4 g/L in the control group (P < .01). There were no significant differences in caloric intakes, length gain, head circumference gain, feeding intolerance, and incidence of necrotizing enterocolitis.

Conclusions: Weight gain may be enhanced during the period of low functional lactase activity of prematurity by addition of lactase to preterm feeds. No adverse effects on feeding tolerance resulted from this treatment.

Comment: Premature infants are usually lactase deficient. At 28-34 weeks EGA, babies have only about 30% of the lactase activity of term babies. This deficiency can lead to feeding intolerance, loose stools, and decreased weight gain in preterm infants fed a lactose-rich diet. These problems are frequently addressed by giving preterm babies with feeding intolerance protein-hydrolysate or lactose-free formulas, but these formulas do not meet the nutritional requirements of premature babies. The strategy employed in this study was to add Lactaid drops (2 drops / 120 ml) to expressed breast milk or premature infant formula and to incubate for 2 hours at room temperature prior to feeding. This should be sufficient to decrease the lactose concentrations of the milk by about 70%. Babies given lactase-treated feedings had better early weight gains, and no adverse effects were noted. This seems like a reasonable option for premature babies with feeding intolerance – or maybe as a routine initial diet for premature infants until feeding tolerance is established. Further studies of the efficacy and safety of this practice are needed. ABK.