Effect of vaginal seeding on the infant stool and skin microbiota.
Vaginal seeding significantly increased bacterial load in the skin (forearm; average, 32 copies/μL versus 14 copies/μL, in seeded and control babies, respectively; Compared with the control, vaginal seeding caused a significant reduction in alpha diversity (Shannon index) in the skin at day 1 (Treatment (seeding versus control) explained considerable variance in the beta diversity of the skin microbiota of day 1 neonates (Principal-coordinate Analysis of infant microbiota beta diversity (weighted UniFrac) by treatment group. (A) Transitional stool. (B) Day 30 stool. (C) Day 1 skin. A permutational multivariate analysis of variance (PERMANOVA) test was performed, and statistical results were noted on the top of each panel. Download Relative to the control, vaginal seeding altered the relative abundance of multiple bacterial amplicon sequence variants (ASVs), causing a decrease in the relative abundance of 5 ASVs in the transitional stool (detected by the analysis of compositions of microbiomes [ANCOM] method) (Log