Fortification with bovine colostrum enhances antibacterial activity of human milk.

OBJECTIVES: Human milk (HM) is most appropriate for neonates, but it does not provide enough nutrients for preterm infants. HM fortifiers based on highly processed mature bovine milk (BMF) are routinely used for preterm infants despite risks of causing gut dysfunction and systemic infection. Bovine colostrum processed by mild thermal treatment as a fortifier (BCF) may better protect against infection and inflammation. We hypothesized that BCF-fortified HM has enhanced antimicrobial activity against pathogens commonly causing neonatal sepsis, relative to BMF-fortified HM. METHODS: Holder-pasteurized HM samples (10 mothers) were aliquoted into three fractions: unfortified HM, HM fortified with either BMF or BCF. The samples were analysed for pH, lactoferrin concentrations, and antimicrobial activities against S. epidermidis, E.coli and E. faecalis. RESULTS: HM+BCF had a lower pH and higher levels of lactoferrin than HM+BMF, with HM being intermediate. Relative to IF, HM decreased the growth of S. epidermidis and E.coli and E.faecalis, with no difference between preterm and term HM. Addition of BMF abolished the antimicrobial effect of HM against S. epidermidis and E.faecalis, but not E.coli. In contrast, addition of BCF into HM enhanced antimicrobial activity against S. epidermidis and E.coli, relative to unfortified HM. HM+BCF was superior to HM+BMF in inhibiting growth of all tested bacteria. CONCLUSION: BMF fortification decreased while BCF fortification enhanced in vitro antimicrobial activity of HM. This effect may partly be derived from the high levels of antimicrobial factors found in BCF, including lactoferrin. BCF may be a better fortifier than BMF for preterm infants. This article is protected by copyright. All rights reserved.