REVIEW / SYNTHÈSE Effect of pasteurization on immune components of milk: implications for feeding preterm infants Julia B. Ewaschuk, Sharon Unger, Sarah Harvey, Deborah L. O’Connor, and Catherine J. Field Abstract: It has been unequivocally proven that human breast milk is the ideal source of nutrition for infants. However, mothers of preterm infants face a number of barriers to providing sufficient milk volume to their babies, who are at risk for developing necrotizing enterocolitis (NEC). Donated milk, distributed through milk banks, is becoming a desirable alterna- tive to formula feeding, and is increasingly being considered for hospitalized, preterm infants in North America. Donor milk in North America is pasteurized (62.5 °C, 30 min) to remove possible infectious contaminants; a number of immune and bioactive components are either partially or entirely inactivated by this process. Identifying the impact of pasteurization on immune components of breast milk has been the focus of numerous research studies over the past several decades. The objective of this review is to summarize the literature on the feeding of pasteurized donor milk to preterm infants and the current understanding of the impact of pasteurization on immune components of breast milk, with particular reference to those implicated in the prevention of NEC. Key words: donor milk, pasteurization, necrotizing enterocolitis, immune, preterm infants. Résumé : On sait sans équivoque, études à l’appui, que le lait maternel est la meilleure source d’alimentation du nourrisson. Toutefois, les mères d’enfants prématurés rencontrent quelques problèmes concernant la quantité suffisante de lait à donner à leur bébé, ce dernier étant à risque de contracter l’entérocolite nécrosante (NEC). Les dons de lait dans les banques de lait humain constituent une bonne solution de rechange à l’allaitement artificiel et sont de plus en plus envisagés pour les en- fants prématurés en milieu hospitalier en Amérique du Nord. Le lait dans les banques en Amérique du Nord est pasteurisé (62,5 °C, 30 min) afin de détruire le plus de contaminants infectieux; ce procédé inactive partiellement ou entièrement des constituants bioactifs et immunitaires. Au cours des quelques décennies précédentes, il y a eu passablement de recherches sur l’impact de la pasteurisation sur les constituants immunitaires du lait maternel. Le but de cette analyse documentaire est de faire le tour des études sur l’alimentation par des dons de lait pasteurisé à des enfants prématurés et de dresser le bilan des connaissances actuelles sur les effets de la pasteurisation sur les constituants immunitaires du lait maternel, notamment en ce qui concerne la prévention de la NEC. Mots‐clés : don de lait, pasteurisation, entérocolite nécrosante néonatale, immunitaire, enfant prématuré. [Traduit par la Rédaction] Introduction Human breast milk is the ideal source of nutrition for in- fants (Tully et al. 2001). The American Academy of Pedia- trics, the Canadian Pediatric Society, and the World Health Organization (WHO) recommend exclusive breastfeeding from within an hour of birth for the first 6 months of life for all healthy women and infants, and to continue breastfeeding for up to 2 years and beyond (AAP Committee on Nutrition 2009; Canadian Paediatric Society, Dietitians of Canada, and Health Canada 2005; WHO 2010). In cases where the bio- logical mother’ s milk is not available to the infant, as can oc- cur upon preterm delivery, an alternative is donor milk. Contamination of donor milk has been reported with coagulase- negative Staphylococcus; Klebsiella, Enterobacter, and Ser- ratia species; Escherichia coli; and cytomegalovirus (Land- ers and Updegrove 2010; Lindemann et al. 2004). Thus, in all milk banks, donor milk is pasteurized to avoid potential transmission of infectious agents by heating it to 62.5 °C for 30 min (Holder pasteurization). The effect of pasteuriza- tion on some components of milk has been investigated, and reductions in various bioactive components have been Received 2 September 2010. Accepted 27 November 2010. Published at www.nrcresearchpress.com/apnm on 13 April 2011. J.B. Ewaschuk and C.J. Field. Department of Agricultural, Food, and Nutritional Sciences, University of Alberta, 4126 HRIF East, Edmonton, AB T6G 2E1, Canada. S. Unger, S. Harvey, and D.L. O’Connor. The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada. Corresponding author: C.J. Field (e-mail: Catherine.Field@ualberta.ca). 175 Appl. Physiol. Nutr. Metab. 36: 175–182 (2011) doi:10.1139/H11-008 Published by NRC Research Press Appl. Physiol. Nutr. Metab. Downloaded from www.nrcresearchpress.com by University of Alberta on 07/25/11 For personal use only.