A related commentary discusses this research. It highlights that prevention of late-onset neonatal sepsis (LOS) in infants born very preterm (<32 weeks’ gestation) is paramount because of its associated mortality and morbidity. Lactoferrin has antimicrobial properties is thought to have to potential to be preventive. As indicated by this study however, future research to reduce LOS and necrotising enterocolitis in very preterm infants should look beyond bovine lactoferrin supplementation.