Protective Effect Of Bifidobacterium On Necrotizing Enterocolitis Mouse Model

Objective:To explore the protective effect of Bifidobacterium in neonatal necrotizing enterocolitis mouse model and discuss the possible mechanism of action.Methods:According to the random number table method,sixty C57BL/6 mice were divided into 3 groups:control group?n=20,mother feeding without any treatment?,NEC group?n=20,formula feeding,hypoxia and cold stimulation?and NEC+BIF group?n=20,NEC induction plus Bifidobacterium?,samples were collected after 3 days'modeling.To observe whether there are any intestinal pneumatosis or bleeding;HE staining pathological score was used to evaluate the severity of intestinal damage;the protein expression of endothelial nitric oxide synthase?eNOS?in intestine was estimated with Western blotting;the activity of eNOS,the concentration of nitric oxide?NO?and superoxide?O₂·–?were measured by colorimetry;Real-time quantitative PCR was used to detect the expression of interleukin-6?IL-6?and interleukin-1??IL-1??in mRNA level;the protein expression of IL-6 and IL-1?was assessed by ELISA.Results:The NEC mouse model were successfully established.No significant difference was observed in the protein expression of eNOS in the three groups.Compared with the control group,the weight of mice in NEC group was markedly reduced,the pathological score of ileocecal intestine was obviously increased,the activity of eNOS?P<0.05?and the concentration of NO?P<0.05?were decreased,while the concentration of O₂·–was increased?P<0.05?,the expression of IL-6 and IL-1?were significantly increased?P<0.05?at the levels of genes and proteins;the mice in NEC+BIF group showed a significant increase in weight and an obvious decrease in pathological score after 3 days'modeling compared with the mice with NEC,the activity eNOS was enhanced?P<0.05?,the concentration of NO was increased?P>0.05?,the concentration of O₂·–was decreased?P<0.05?,IL-6 was significantly decreased in protein level?P<0.05?,IL-1?was obviously decreased in both gene and protein level?P<0.05?.Conclusion:Bifidobacterium plays a protective role in NEC mouse model,the mechanism of which may be related to the eNOS activity improved by Bifidobacterium.