Abstract
Background: Human milk (HM) feedings are associated with reduced risks of neurodevelopmental and neurocognitive delays, and inflammatory diseases, in infants born prematurely and/or at a low birth weight. However, due to confounding variables, such as caregiver education level and culture, and the ethical considerations involved in studying neurodevelopment in infants, a neonatal piglet model was utilized in this study. HM feedings were compared to preterm bovine infant formula (PIF)-feedings with the hypothesis that HM feedings would result in neurodevelopmental and neurocognitive improvements by decreasing systemic inflammation. Methods: Six Yorkshire-Duroc cross male piglets at postnatal-day (PD)2 were randomized into two feeding groups: HM-fed (n = 3) or PIF-fed (n = 3) for 28 days. At 3- and 4-weeks-old, piglet memory and learning performance was assessed using novel object recognition (NOR). At PD30 piglets were euthanized and brain weight measured. Brain microglial morphology was assessed, and systemic inflammatory cytokines were quantified. All statistical analyses were conducted using R. Multiple linear models were generated for NOR followed by estimated marginal means and their associated pairwise comparison t-tests. Piglet weights (body and brain), brain morphology, and systemic cytokines (IL-6, IL-8, IL-10, TNF-?, and IL-1?) were analyzed using independent samples t-tests or Mann-Whitney U tests.
Results: HM-fed piglets spent significantly more time in the center of the arena and had more center visits compared to PIF-fed piglets at 4-weeks-old (p = 0.025). PIF-fed piglets traveled significantly more distance and spent more time moving at 3-weeks-old compared to 4-weeks-old (p = 0.048).
Conclusions: In a neonatal piglet model, HM-feedings improved cognition with a trend towards larger normalized brain size compared to PIF-feedings. Future studies are indicated to further investigate more brain changes as a function of feedings.