Can Enterococcus faecium prevent NEC in preterm infants?: A systematic review and meta-analysis

Previous some systematic reviews reported that probiotics may benefit the prevention of NEC in preterm infants. But dissimilar bacterial strains and taxa used in included studies possibly result in bias. There is not a rounded systematic review which has estimated the benefit and safety of Enterococcus faecium to prevent NEC in preterm infants to date before we conducted. METHODS: This systematic review of randomized controlled trials and retrospective studies analyzing the benefit of Enterococcus faecium to prevent NEC in preterm infants was performed using PubMed, Web of Science, Cochrane Library, EMBASE, Wanfang data and China National Knowledge Infrastructure databases from inception to April 14, 2023. The search terms were “preterm” AND “necrotizing enterocolitis” AND “Enterococcus faecium OR probiotics.” Studies reporting NEC involving preterm infants who were given Enterococcus faecium were included in this systematic review. A sensitivity analysis was conducted to assess the stability of results. A funnel plot was generated to identify publication bias. Two authors appraised studies quality and extracted data independently. This work has been reported according with preferred reporting items for systematic reviews and meta-analyses and assessing the methodological quality of systematic reviews. Statistical analysis was conducted using Review Manager 5.3 software. Risk ratio (RR) with 95% confidence intervals (CI) was calculated and analyzed. RESULTS: Seven studies (N = 1487 participants) were included in this systematic review, and 6 randomized, controlled trials (N = 1237 participants) were included in the meta-analysis. Comparing with the control groups, the Enterococcus faecium groups had a significant decline in the incidence of NEC Bell stage II or higher (RR: 0.3138, 95% CI: 0.1983–0.4965; P < .00001; 6 studies, n = 1237) and infection (RR: 0.4818, 95% CI: 0.2950–0.7869; P = .004; 3 studies, n = 710). CONCLUSIONS: Enterococcus faecium is effective and safe in preventing NEC (Bell stage II or higher) in preterm infants. But all studies included came from China. The dosages and durations of taking Enterococcus faecium were various.