Neonatal Antibiotic Exposure Alters Compositional Gut Microbiota Development During the First 6 Months of Life

Abstract

ObjectiveTo investigate the impact of neonatal antibiotic exposure on gut microbiota development in infants born after 36 weeks of gestationMethodsA case‐control study of 6 neonates exposed to brief (<5 days) empirical antibiotics (penicillin G and gentamicin) during the first 72 hours of life, 6 neonates receiving a 7‐day course of the same antibiotics for documented infection and 24 matched healthy non‐exposed neonates. Gut microbiota composition was assessed at 1 and 6 months of age by qPCR, DGGE and 16S rRNA pyrosequencingResultsNeonatal antibiotic exposure resulted in a significant decrease in fecal bifidobacteria at 1 month of age (p=0.015), particularly in B. bifidum (p=0.0061). The bacterial richness of infants exposed to antibiotics was significantly lower compared to non‐exposed infants. The principal coordinates analysis (PCoA) formed separate clusters when compared between antibiotic‐exposed and non‐exposed infants at 6 months of age. In particular, an increased frequency of Firmicutes and a decrease in Bacteroidetes was observed in antibiotic‐exposed infantsConclusionsAberrant gut microbiota colonization is attributable to antibiotic exposure since it was observed also in antibiotic‐exposed neonates in whom infection was later ruled out. Decreased levels of both bifidobacteria and Bacteroidetes in early infancy have previously been linked to increased risk for non‐communicable disease in later life. Means of accurately detecting bacterial infections in neonates are needed to avoid unnecessary exposure to antibiotics during this vulnerable periodResearch supportFunctional Foods Forum, University of Turku