“a baby’s suckling at the breast creates a vacuum; the ensuing “baby spit backwash” delivers messages to the mother’s mammary gland receptors. If a particular pathogen is identified, the mother’s body begins to produce antibodies to fight it, which then travel back to the baby’s body. This explains why there can be a significant change in the color of breast milk when your baby is sick. Your body adjusts to provide milk that is closer to the nutrient-dense colostrum that you first produced in order to provide illness-fighting antibodies to your baby. You have information about your whole lifespan that could be in your milk, pointing to the fact that vegetarian mothers who ate meat as teenagers still pass on those fatty acids to their infants. Milk is telling the baby about the world its mother has lived in.”