Growth inhibition of common neonatal pathogens differs between bovine lactoferrin products

<b>Introduction.</b> Infection is a leading cause of mortality during the first year of life, with the neonatal period being particularly high risk. It is critical to identify non-antibiotic approaches to improve neonatal infection outcomes due to the non-specific clinical signs of neonatal infection and negative consequences of early-life antibiotic exposure. Lactoferrin is a protein found in all mammalian milk that has a variety of antimicrobial properties. Clinical trials have shown that lactoferrin supplementation during the neonatal period decreases rates of sepsis.<b>Knowledge Gap.</b> It remains unclear if there is an optimal lactoferrin preparation for human neonates.<b>Aim.</b> Compare bacterial growth inhibition capabilities between different commercially available bovine-derived lactoferrin (bLF) preparations.<b>Methodology.</b> This study uses a broth microdilution <i>in vitro</i> assay to directly compare the antibacterial effects and shelf stability of different bLF preparations against three common neonatal pathogens: <i>Escherichia coli</i>, <i>Klebsiella pneumoniae</i> and <i>Streptococcus pneumoniae</i>.<b>Results.</b> Bacterial growth inhibition differed significantly between bLF manufacturers and between different bLF lots/batches from the same manufacturer. Approximately half of the bLF products demonstrated decreased bacterial growth inhibition capabilities within 7-14 days after solubilization.<b>Conclusion.</b> These findings may help select optimal bLF products for clinical use in the neonatal population, but additional <i>in vivo</i> studies are needed to confirm our <i>in vitro</i> findings.