Deciphering the effect of maternal postpartum antibiotic prophylaxis on the infant gut microbiome: a whole metagenomic analysis.

To analyze the impact of postpartum antibiotic (Ab) prophylaxis on the infant gut microbiome. Whole metagenomic analysis was performed on breast milk and infant fecal samples collected from mother-infant pairs who belonged to two groups: an Ab group comprising mothers who had received a single course of Abs in the immediate postpartum period and a non-Ab group comprising mothers who had not received Abs. The characteristic presence of , an emerging multidrug-resistant uropathogen, and a higher relative abundance of genes encoding resistance to specific Abs were noted in samples from the Ab group compared with those from the non-Ab group. Policies regarding prophylactic Ab prescription across government and private health sectors in the postpartum period need to be strengthened.