Protective Effect of Dual-Strain Probiotics in Preterm Infants: A Multi-Center Time Series Analysis

OBJECTIVE To determine the effect of dual-strain probiotics on the development of necrotizing enterocolitis (NEC), mortality and nosocomial bloodstream infections (BSI) in preterm infants in German neonatal intensive care units (NICUs). DESIGN A multi-center interrupted time series analysis. SETTING 44 German NICUs with routine use of dual-strain probiotics on neonatal ward level. PATIENTS Preterm infants documented by NEO-KISS, the German surveillance system for nosocomial infections in preterm infants with birth weights below 1,500 g, between 2004 and 2014. INTERVENTION Routine use of dual-strain probiotics containing Lactobacillus acidophilus and Bifidobacterium spp. (Infloran) on the neonatal ward level. MAIN OUTCOME MEASURES Incidences of NEC, overall mortality, mortality following NEC and nosocomial BSI. RESULTS Data from 10,890 preterm infants in 44 neonatal wards was included in this study. Incidences of NEC and BSI were 2.5% (n = 274) and 15.0%, (n = 1631), respectively. Mortality rate was 6.1% (n = 665). The use of dual-strain probiotics significantly reduced the risk of NEC (HR = 0.48; 95% CI = 0.38-0.62), overall mortality (HR = 0.60, 95% CI = 0.44-0.83), mortality after NEC (HR = 0.51, 95% CI = 0.26-0.999) and nosocomial BSI (HR = 0.89, 95% CI = 0.81-0.98). These effects were even more pronounced in the subgroup analysis of preterm infants with birth weights below 1,000 g. CONCLUSION In order to reduce NEC and mortality in preterm infants, it is advisable to add routine prophylaxis with dual-strain probiotics to clinical practice in neonatal wards.