Bifidobacterium and Lactobacillus for preventing necrotizing enterocolitis in very-low-birth-weight preterm infants: a systematic review and meta-analysis

Background The therapeutic effect of Bifidobacterium and Lactobacillus on necrotizing enterocolitis (NEC) in very-low-birth-weight preterm infants was controversial, and we aimed to explore the exact impact of the two probiotics. Methods The PubMed, EMBASE, Web of Science and Cochrane Library were systematically searched for studies published from January 1, 2010 to February 28, 2019. Results were combined with fixed-effect model or random-effect model with specific conditions. Sensitivity analysis was conducted by the trim-and-fill method, and the Begger's and Egger's test were used to measure publication bias. Results The meta-analysis included 16 original articles with 4632 very-low-birth-weight preterm infants. With respect to the intervention of Bifidobacterium, we estimated non-significant decrease in the morbidity of NEC with a risk ratio (RR) of 0.75 [95% confidence internal (CI) 0.56-1.01, P = 0.06]. Regarding the effect of Lactobacillus, there was no evidence of significant lower risk in the incidence of NEC (RR = 0.67, 95% CI 0.39-1.17, P = 0.16). The use of mixture of probiotics (Bifidobacterium and Lactobacillus) reduced the risk of NEC in the probiotics group (RR = 0.45, 95% CI 0.25-0.80, P = 0.007). Conclusion The mixture of Bifidobacterium and Lactobacillus could prevent the morbidity of NEC in very-low-birth-weight preterm infants. But Bifidobacterium or Lactobacillus alone did not show this effect.