Probiotic supplementation - does it prevent or cause neonatal sepsis?

Probiotic supplementation in preterm infants is one of the most extensively studied interventions in neonatal medicine, with over 50 randomised controlled trials. This paper examines the relationship between probiotic supplementation and late onset sepsis (LOS), considering mechanistic pathways, clinical evidence, and safety profile. Multiple systematic reviews and meta-analyses consistently show that probiotics reduce necrotising enterocolitis (NEC) incidence and all-cause mortality in preterm infants, establishing them as one of the most beneficial interventions in neonatology. Current evidence suggests modest effects on LOS, with Cochrane systematic reviews reporting relative risk 0.89 (95 % CI 0.82-0.97) but with low certainty. Mechanisms supporting LOS reduction include competitive pathogen exclusion, enhanced epithelial barrier function, improved immune responses, and reduced time to full enteral feeding with decreased intravenous access requirements. The safety profile of probiotics is reassuring, with serious adverse events being exceptionally rare. Probiotic-induced sepsis probably occurs in less than 0.5 % of treated infants, representing a very low risk that must be weighed against the likely substantial benefits for NEC and mortality reduction. Product contamination and other quality issues exist but appear manageable with appropriate quality control. Given the robust evidence for NEC and mortality reduction, probiotics represent a valuable intervention for preterm infants but may have limited, if any impact on sepsis. While their specific role in LOS prevention and impacts on the resistome requires further investigation, the overall benefit-risk profile strongly favors their use. Future research will further refine understanding of optimal strain selection and implementation strategies for maximizing clinical benefits while maintaining safety.