Immune tolerance produced by pre- and postnatal exposure to dietary antigens.

Circulating food antibody levels were measured by ELISA in groups of weanling rabbits fed 320 g/kg diet soya or milk protein. Soya-fed rabbits of milk-fed mothers (and vice versa) showed at least tenfold increase in antibody levels within 3-4 weeks. In contrast, animals fed the same diet as their dams had received in pregnancy and the postnatal period showed little change in antibody levels. These results indicate that contact with a dietary antigen before birth and during the suckling period is important in the induction of tolerance to food proteins in young animals.