Impact of maternal intrapartum antibiotics on the initial oral microbiome of neonates.

OBJECTIVES: Prior studies have proposed that maternal intrapartum antibiotic exposure shapes the gut microbiota and, subsequently the child's health. However, the effect of maternal intrapartum antibiotic exposure and its influence on the development of the neonatal oral microbiota in early infancy has not yet been reported. The aim of this study was to compare the initial oral microbiota immediately after birth of healthy infants with and without intrapartum antibiotic exposure.

METHODS: Twenty-two newborns of the BaoAn Maternal and Child Care Hospital (Shenzhen, China) were recruited for this study, 11 born to mothers without intrapartum antibiotic exposure (NT group) and 11 to mothers with intrapartum antibiotic prophylaxis with cefamezin (AT group). Oral microbiome profiles were determined by 16S rRNA sequencing based on the V3V4 hyper-variable regions.

RESULTS: Phylum Firmicutes was most frequently detected in subjects both groups and a higher frequency was observed in the NT group than the AT group. Phyla Actinobacteria, Bacteroidetes and Proteobacteria were more abundant after intrapartum antibiotics exposure. Genus Lactobacillus belonging to Firmicutes was predominant in the neonates not exposed to antibiotics, while significantly higher percentages of genera Klebsiella, Roseburia, Propionibacterium, Faecalibacterium, Escherichia/Shigella, Corynebacterium, Bifidobacterium, and Bacteroides were noted in AT infants than NT infants. Further function analysis demonstrated that lipopolysaccharide biosynthesis and amino acid-related metabolic function was enriched in the AT group, and carbohydrate metabolism pathways were more abundant in the NT group.

CONCLUSIONS: These findings revealed distinctions in both taxa and metabolic function of oral microbiota between antibiotics-treated and unexposed groups, which indicated that maternal intrapartum antibiotic treatment is a key regulator of the initial neonatal oral microbiome.