Background: Donor human milk is considered the next best nutrition following mother's own milk to prevent neonatal infection and necrotizing enterocolitis in preterm infants who are admitted at neonatal intensive care unit. However, donor milk biofunctionalities after preparative processes have rarely been documented.
Objective: To evaluate biofunctionalities preserved in donor milk after preparative processes by cell-based assays.
Materials and methods: Ten pools of donor milk were produced from 40 independent specimens. After preparative processes, including bacterial elimination methods (holder pasteurization and cold-sterilization microfiltration) and storage conditions (-20°C freezing storage and lyophilization) with varied duration of storage (0, 3, and 6, months), donor milk biofunctionalities were examined by fetal intestinal cell growth and antimicrobial assays.
Results: At baseline, raw donor milk exhibited 193.1% ± 12.3% of fetal intestinal cell growth and 42.4% ± 11.8% of antimicrobial activities against Escherichia coli. After bacteria eliminating processes, growth promoting activity was better preserved in pasteurized donor milk than microfiltrated donor milk (169.5% ± 14.3% versus 146.0% ± 11.8%, respectively; p < 0.005), whereas antimicrobial activity showed no difference between groups (38.3% ± 14.1% versus 53.7% ± 17.3%, respectively; p = 0.499). The pasteurized donor milk was further examined for the effects of storage conditions at 3 and 6 months. Freezing storage, but not lyophilization, could preserve higher growth-promoting activity during 6 months of storage (163.0% ± 9.4% versus 72.8% ± 6.2%, respectively; p < 0.005). Nonetheless, antimicrobial activity was lost at 6 months, regardless of the storage methods.
Conclusions: This study revealed that fetal intestinal cell growth and antimicrobial assays could be applied to measure donor milk biofunctionalities and support the utilization of donor milk within 3 months after preparative processes.
Keywords: antimicrobial activity; donated breast milk; donor milk preparation; fetal intestinal cell growth; human milk bank.