Another example of a potential use for bovine immunoglobulin preparations to control bacterial populations comes from studies on dental caries formation [69] . The concept of prenatal immunization of the pregnant mother to protect the neonate against dental caries was demonstrated in rats [70] . In applications to humans, bovine whey preparations of colostrum from cows immunized with caries-inducing bacterial strains (Streptococcus mutans and Streptococcus sobrinus), and containing over 60% immunoglobulin of which 80% was IgG1, has been used in several studies evaluating its effect on caries-producing bacteria. The colostral whey preparation reduced adherence of Streptococcus mutans in vitro and caused aggregation of suspended bacteria [71] , as well as inhibited glucose uptake by the test organism [72, 73] . The whey preparation from hyperimmunized cows opsonized bacteria and enhanced in vitro phagocytosis of bacteria by human leukocytes [74] .