Research Progress on Probiotics and the Development of Gut Microbiota and Immune System in Newborns

Abstract

The neonatal period is a critical window for gut microbiota colonization and immune development. This article systematically reviews the research progress of probiotics in regulating gut microbiota, immune modulation, disease prevention, and safety in newborns. Full-term and preterm infants show different responses to probiotics, with the latter exhibiting more severe dysbiosis; probiotics can increase beneficial bacteria and reduce pathogenic bacteria. Metabolomics reveals that the metabolic function mediated by short-chain fatty acids (acetate, lactate) produced by probiotics is more critical than simple colonization in preventing late-onset sepsis. High-level clinical evidence indicates that probiotics significantly reduce the risk of necrotizing enterocolitis (pooled RR = 0.51) and all-cause mortality (pooled RR = 0.72) in preterm infants, with multi-strain formulations showing better efficacy; a consistent protective effect is also observed against late-onset sepsis. Early supplementation with infant-type bifidobacteria in full-term infants reduces the risk of eczema (RR = 0.78). Probioticassociated invasive infections are rare, and the benefit/risk ratio is favorable under strict quality control.