Assessment of the Protective Effects of Milk Osteopontin in Necrotizing Enterocolitis Neonatal Rat Model.

Osteopontin (OPN) is a multifunctional milk protein with various potential health benefits. However, studies on the role of OPN during early life are still very limited. This study employed a neonatal rat model to investigate the protective effects of milk OPN against necrotizing enterocolitis (NEC), a devastating gastrointestinal disease leading high morbidity and mortality in infants. In NEC-affected rat pups, milk OPN enhanced the survival rates, and alleviated the ileum tissue damage. Immunofluorescence staining revealed that milk OPN significantly promoted intestinal cell proliferation and migration (p < 0.05). Moreover, milk OPN was found to reduced the expression of pro-inflammatory cytokines IL-6 and TNF-α in ileum tissue (p < 0.05). The activation of Toll-like receptor 4 (TLR4) and nuclear factor kappa-B (NF-κB), which are key regulators of cell proliferation and inflammation in NEC, were inhibited by milk OPN. Additionally, gut microbiota composition was also improved by milk OPN, with a reduction in the abundance of inflammation-associated bacteria, such as Proteobacteria and Klebsiella (p < 0.05), which are Gram-negative bacteria capable of activating TLR4 signaling. Our findings demonstrate the protective effects of milk OPN on NEC and propose that milk OPN may be utilized as a preventive measure against inflammatory intestinal diseases in early developmental stages.