Effect of Bifidobacterium lactis on the incidence of nosocomial infections in very-low-birth-weight infants: a randomized controlled trial

Abstract

Background: Nosocomial infections endanger preterm infants.

Objective: The aim of the present controlled randomized trial was to investigate whether Bifidobacterium lactis reduces the incidence of nosocomial infections in infants with very low birth weight (VLBW; <1,500 g) <30 weeks of gestation.

Patients and methods: In a randomized controlled trial, 183 VLBW infants <30 weeks of gestation were stratified according to gestational age (23-26 and 27-29 weeks) and early antibiotic therapy (days 1-3, yes or no) and randomly assigned to have their milk feedings supplemented with B. lactis (6 x 2.0 x 10(9) CFU/kg/day, 12 billion CFU/kg/day) or placebo for the first 6 weeks of life. Primary outcome was the 'incidence density' of nosocomial infections defined as periods of elevated C-reactive protein (>10 mg/l) from day 7 after initiation of milk feedings until the 42nd day of life (number of nosocomial infections/total number of patient days). The main secondary outcome was necrotizing enterocolitis (NEC; >or=stage 2).

Results: There were 93 infants in the B. lactis group and 90 in the placebo group. There was no significant difference between the two groups with regard to the incidence density of nosocomial infections (0.021 vs. 0.016; p = 0.9, chi(2) test). There were 2 cases of NEC in the B. lactis group and 4 in the placebo group. None of the blood cultures grew B. lactis.

Conclusion: In the present setting, B. lactis at a dosage of 6 x 2.0 x 10(9) CFU/kg/day (12 billion CFU/kg/day) did not reduce the incidence density of nosocomial infections in VLBW infants. No adverse effect of B. lactis was observed.