Bacteroides fragilis Strain ZY-312 Defense against Cronobacter sakazakii-Induced Necrotizing Enterocolitis In Vitro and in a Neonatal Rat Model

Abstract

Cronobacter sakazakii is an opportunistic pathogenic bacterium that can cause necrotizing enterocolitis (NEC). However, the mechanism of pathogenicity of C. sakazakii is largely unknown. Here we have now demonstrated that apoptotic and pyroptotic stimuli are effectors of C. sakazakii -induced NEC. Previously, we isolated a novel probiotic strain candidate from fecal samples from healthy infants and characterized it as Bacteroides fragilis strain ZY-312. Functional characterization reveals that ZY-312 inhibited C. sakazakii invasion, restoring epithelial barrier dysfunction, decreasing the expression of inflammatory cytokines, and reducing dual cell death (pyroptosis and apoptosis). Furthermore, the presence of ZY-132 was sufficient to hinder the adverse reaction seen with C. sakazakii in a C. sakazakii -induced NEC model. Taking the results together, our study demonstrated the utility of ZY-312 as a promising probiotic agent for the prevention of NEC.