Probiotics for prevention of necrotising enterocolitis: an updated meta-analysis.

Several randomized controlled trials (RCTs) have investigated the prophylactic use of probiotics in preterm infants aimed at reducing the rate of necrotising enterocolitis (NEC). There are 4 meta-analyses on this subject. 2 more RCTs have been published since these meta-analyses were completed. Each meta-analysis, as well as the 2 recent RCTs, document reduced rates of NEC and mortality with the use of prophylactic probiotics. We calculated meta-analyses based on 3 approaches: A - RCTs common to all meta-analyses, B - RCTs ever accounted for in a meta-analysis but not common to all, and C - the 2 recent RCTs. The 3 subgroups yield similar results, with an overall reduction in the relative risk (RR) of NEC (Bell > or =2) to 0.35 (95% CI 0.23-0.55) and of mortality to 0.41 (0.28-0.60). NEC rates and mortalities in the dominant RCTs are in the range reported from North American and European networks. Best results appear to be achieved with probiotics based on 2 or more probiotic species and/or with a combination of Bifidusbacterium spp. and Lactobacillus acidophilus. No unwanted side effects have been reported among 1 117 infants randomized to receive probiotics. We conclude that probiotics are safe and beneficial in preterm infants at risk for NEC.