A Neonatal Mouse Model of Necrotizing Enterocolitis and Lamina Propria Isolation for Immune Cell Profiling.

Necrotizing enterocolitis (NEC) is a severe inflammatory disease of the neonatal intestine, primarily affecting preterm infants. NEC is characterized by epithelial injury, microbial dysbiosis, and a dysregulated immune response, often resulting in intestinal necrosis and systemic inflammation. Experimental murine models that recapitulate the key aspects of human disease have been essential in advancing our understanding of the mechanisms that drive disease and inform therapeutic development. This protocol describes a well-established neonatal mouse model of necrotizing enterocolitis (NEC) utilizing formula feeding, intermittent hypoxia, oral administration of lipopolysaccharide (LPS), and enteric bacteria cultured from an infant with NEC. This combination reliably induces histological, transcriptional, and immunological features consistent with NEC in human infants and has been foundational in multiple key discoveries in the field. Additionally, this protocol describes the isolation of immune cells from the small intestinal lamina propria of neonatal mice. Lamina propria cell isolation enables detailed immune cell profiling via flow cytometry, facilitating analysis of both innate and adaptive cell populations within the intestine.