Abstract Late-onset neonatal sepsis (LOS), an important cause of morbidity and mortality in prematurely born infants, results from a bloodstream infection by bacteria of gut origin. It remains unclear how such bacteria translocate from the intestine, though it has been repeatedly observed that breastfed infants, particularly those fed mother’s own milk (MOM), have reduced risk of LOS compared to formula fed infants. Epidermal growth factor (EGF) promotes intestinal barrier function in infants and is present at high concentrations in breast milk post-partum and decreases throughout lactation. We found reduced concentrations of EGF in the stool of premature formula-fed infants compared to MOM-fed infants, and observed a similar decrease in EGF concentrations of stool of neonatal mice asynchronously cross-fostered (ACF) to dams that had delivered two weeks prior. LOS bloodstream isolates of E. coli colonized the tracts of all pups but translocated and disseminated systemically only in ACF mice resulting in bacteremia and rapid death. Oral gavage of recombinant EGF reduced bacteria translocation and prevented the development of systemic disease in ACF mice. Thus, disruption of maternally delivered EGF in ACF mice results in translocation of pathogens from the gut, and a sepsis-like disease. In conclusion we have identified a mechanism whereby gut-residing pathogens gain systemic access and have developed a novel animal model replicating this mechanism to explore the protective effect of breastmilk and EGF in LOS.