C-Section Ups Baby's Risk of Milk Intolerance
According to an article in the journal Allergy, children delivered via cesarean section are twice as likely to become allergic to cow's milk, compared with children delivered vaginally.
Researchers speculate that infants born vaginally are exposed to more bacteria than are babies born via c-section. In turn, vaginally born infants have more normal intestinal bacteria, allowing them to digest cow's milk properly.
Allergy - September 2005;60:1172.