Probiotics to prevent necrotising enterocolitis in very preterm infants.

Introduction: Meta-analyses of randomised trials have shown that probiotics reduce the risk of necrotising enterocolitis (NEC) in preterm infants. However, the generalisability of these results, particularly for the most preterm infants, remains unresolved. Hence, we wanted to evaluate the benefit of implementing prophylactic use of probiotics as standard care in infants younger than 30 weeks of gestation.

Methods: Two three-year periods were compared. The first period was prior to a policy change. In this period no probiotics were used. The second period featured routine administration of probiotics (bifidobacillus and lactobacillus) once daily by nasogastric tube from the third day of life. The main outcome: NEC grades 2 and 3 were assessed in a blinded fashion from a clinical abstract and available X-rays.

Results: A total of 381 infants treated before the change of policy were compared with 333 infants treated after the policy change had been introduced. There was no statistically significant change in NEC (odds ratio (OR) = 0.75, p = 0.34, 95% confidence interval (CI): 0.43-1.30). The OR for death was 0.92 (p = 0.55, 95% CI: 0.62-1.40). Unexpectedly, symptoms of NEC appeared earlier in the latter period (median six versus 14 days, p = 0.004). No side effects and no blood cultures with lactobacillus or bifidobacterium were observed.

Conclusions: This historically controlled study did not indicate that probiotics had a significant effect on NEC. We continue our practice, but larger cohort studies or meta-analyses of such studies are needed to confirm previous beneficial findings in randomised trials.

Funding: none.

Trial Registration: Clinicaltrials.gov NCT01670916.