Maternal Low‐Fat and High‐Fat Diet Decreases Survival and Alters Cytokine Signaling in Neonatal Mice With <scp> <i>Staphylococcus epidermidis</i> </scp> Sepsis

Maternal malnutrition increases susceptibility to sepsis and mortality in neonates. The reason for this increased susceptibility remains unknown. We aimed to evaluate bacterial burden and serum cytokine levels in septic neonatal mice born to dams fed diets with different dietary fat content. 6-week-old C57BL/6 dams were placed on a low-fat (LFD) (10% kcal from fat), control (CD) (18% kcal from fat), or high-fat (HFD) (60% kcal from fat) diet for 3 weeks before breeding. Sepsis was induced in P4-P6 offspring via intraperitoneal Staphylococcus epidermidis injection. Mice were monitored for survival. At 12 h after sepsis, serum and peritoneal wash fluid were collected for bacterial count and serum cytokine levels. In the absence of infection, P4-P6 offspring had untargeted serum metabolomics performed. Septic offspring of dams fed LFD and HFD had significantly higher mortality than offspring of dams fed CD. There was no difference in serum or peritoneal wash bacterial loads. Maternal diet and S. epidermidis sepsis caused changes in basal serum cytokine levels, with HFD causing decreased cytokine elevation during sepsis. Maternal LFD and HFD altered similar metabolomic pathways in offspring. Maternal LFD and HFD decrease survival during neonatal sepsis and alter serum cytokines and the metabolome, supporting a role for maternal nutrition in neonatal immune function and infection susceptibility.