Study finds infants born vaginally have gut flora similar to mother's vaginal flora--Lactobacillus, Prevotella, or Sneathia species. In contrast, those born via C/S have gut flora similar to that on the skin surface--staphylococcus, corynebacterium...
the usage of antibiotics during the first 6 months of a child's life appears to be associated with an increased risk of overweight in children. There was a slight increased association with mode of delivery (C/S worse than vaginal), but this was not statistical.