Specific class of intrapartum antibiotics relates to maturation of the infant gut microbiota: a prospective cohort study.

<bold>Objective: </bold>To evaluate the potential impact of intrapartum antibiotics, and their specific classes, on the infant gut microbiota in the first year of life.<bold>Design: </bold>Prospective study of infants in the New Hampshire Birth Cohort Study (NHBCS).<bold>Settings: </bold>Rural New Hampshire, USA.<bold>Population or Sample: </bold>Two hundred and sixty-six full-term infants from the NHBCS.<bold>Methods: </bold>Intrapartum antibiotic use during labour and delivery was abstracted from medical records. Faecal samples collected at 6 weeks and 1 year of age were characterised by 16S rRNA sequencing, and metagenomics analysis in a subset of samples.<bold>Exposures: </bold>Maternal exposure to antibiotics during labour and delivery.<bold>Main Outcome Measure: </bold>Taxonomic and functional profiles of faecal samples.<bold>Results: </bold>Infant exposure to intrapartum antibiotics, particularly to two or more antibiotic classes, was independently associated with lower microbial diversity scores as well as a unique bacterial community at 6 weeks (GUnifrac, P = 0.02). At 1 year, infants in the penicillin-only group had significantly lower α diversity scores than infants not exposed to intrapartum antibiotics. Within the first year of life, intrapartum exposure to penicillins was related to a significantly lower increase in several taxa including Bacteroides, use of cephalosporins was associated with a significantly lower rise over time in Bifidobacterium and infants in the multi-class group experienced a significantly higher increase in Veillonella dispar.<bold>Conclusions: </bold>Our findings suggest that intrapartum antibiotics alter the developmental trajectory of the infant gut microbiome, and specific antibiotic types may impact community composition, diversity and keystone immune training taxa.<bold>Tweetable Abstract: </bold>Class of intrapartum antibiotics administered during delivery relates to maturation of infant gut microbiota. [ABSTRACT FROM AUTHOR]