罗伊氏乳杆菌对坏死性小肠结肠炎氧化应激的保护机制

目的探讨罗伊氏乳杆菌（L. reuteri）DSM17938菌株对坏死性小肠结肠炎（NEC）新生小鼠模型氧化应激的保护作用及可 能机制。方法将96只10日龄C57BL/6J新生小鼠随机分为3组（n=32）：对照组、NEC组、NEC+L. reuteri组。通过HE染色观察 回盲部肠组织病理变化并行双盲病理评分。采用实时荧光定量PCR检测肠组织中TNF-α、IL-1β的基因表达水平。通过ELISA 检测肠组织TNF-α、IL-1β的蛋白表达水平。采用比色法检测SOD活力及抑制率、MDA、GSH、GSSG、GSSG/GSH比值。结果 与对照组相比，NEC组小鼠体质量下降（P<0.05），肠道损伤加重，病理评分增加（P<0.05），TNF-α、IL-1β在基因及蛋白水平均表 达升高（P<0.05），SOD活力及抑制率、GSH降低，MDA、GSSG、GSSG/GSH比值显著升高（P<0.05）。与NEC组相比，NEC+L. reuteri 组病理评分降低，TNF-α、IL-1β在基因及蛋白水平均表达降低（P<0.05），SOD活力及抑制率、GSH 增加，MDA、GSSG、 GSSG/GSH比值明显降低（P<0.05），两组生存率差异无统计学意义（P>0.05）。结论L. reuteri DSM17938可能通过减少肠道 氧化应激、增加其抗氧化能力，从而减轻肠道炎症反应，发挥对NEC新生小鼠肠道保护作用。

Protective effect of Lactobacillus reuteri against oxidative stress in neonatal mice with necrotizing enterocolitis

Objective To investigate the protective effect of L. reuteri DSM17938 strain against oxidative stress in a neonatal mouse model of necrotizing enterocolitis (NEC) and explore the possible mechanism. Methods Ninety-six 10-day-old neonatal C57BL/6J mice were equally randomized into control group, NEC group, and NEC+ L. reuteri group. The pathological changes of the ileocecal intestinal tissue were evaluated with HE staining and double-blind pathological scoring. The mRNA and protein expressions of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the intestinal tissues were detected using quantitative real-time PCR and ELISA, respectively. Colorimetric assays were used to determine the activity of superoxide dismutase (SOD) and its inhibition rate, malondialdehyde (MDA), glutathione (GSH), oxidized glutathione (GSSG), and GSSG/ GSH ratio. Results Compared with those in the control group, the neonatal mice in NEC group showed significant weight loss (P<0.05), obvious intestinal injury, increased pathological scores (P<0.05), increased expressions of TNF-α and IL-1β mRNA and proteins (P<0.05), decreased SOD activity and inhibition rate, decreased GSH, and significantly increased MDA, GSSG, and GSSG/GSH ratios (P<0.05). Treatment with L. reuteri obviously decreased the pathological scores, expressions of TNF-α and IL-1β (P<0.05), MDA, GSSG, and GSSG/GSH ratio (P<0.05), and significantly increased SOD activity, its inhibition rate, and GSH level in the mice with NEC, but the survival rate was not significantly different between NEC and L. reuteri-treated groups (P>0.05). Conclusion L. reuteri DSM17938 can offer protection against NEC in mice by reducing oxidative stress and increasing antioxidant capacity of the intestinal tissue to suppress intestinal inflammations.