When human milk is pasteurized via Holder method, the milk is heated to 62.5 degrees C for 30 minutes in a shaking water bath.  We know that several immunological factors become less active in this process, including lysozyme, lactoferrin, lactoperoxidase, and secretory immunoglobulin A.16   However, oligosaccharides are not affected by the pasteurization process.17

Oligosaccharides play very important prebiotic, immunomodulatory and antimicrobial roles in infants. Other immunologic and growth factors also retain activity after pasteurization, such as epidermal growth factor, and transforming growth factors (TGF). Some TGF subtypes have an anti-inflammatory effect upon fetal intestinal cells, which may help to decrease NEC.18