Birth and Feeding Mode

Feeding mode shapes the infant microbiome more strongly after birth than birth mode. C-section babies bypass the vaginal canal and receive antibiotics during the procedure. About 30% of infants retain the C-section signature beyond one year and have a threefold higher risk of asthma and atopic march. Formula-fed infants can show premature microbiome maturation rather than a beneficial increase in diversity. Vaginally born babies receive Lactobacillus, Bacteroides, and continued Bifidobacteria transfer through breast milk.