丁酸钠对胃溃疡模型大鼠肠道炎症和肠道菌群构成的影响

Effects of sodium butyrate on intestinal inflammation and composition of intestinal flora in rats with gastric ulcer

目的探究丁酸钠(NaB)对胃溃疡模型大鼠肠道炎症和肠道菌群构成的影响,为NaB治疗胃溃疡提供实验依据。方法将SPF级SD大鼠(6~8周龄,体重180~240 g)随机分为正常组、模型组、NaB低剂量组、NaB高剂量组和奥美拉唑组,每组8只。采用盐酸+乙醇法建立胃溃疡大鼠模型,NaB低剂量组、NaB高剂量组和奥美拉唑组分别灌胃200 mg/kg NaB溶液、400 mg/kg NaB溶液、20 mg/kg奥美拉唑溶液,每日给药1次,连续给药5 d。评估各组大鼠胃损伤情况,观察胃黏膜病理形态变化,使用荧光定量PCR法检测胃黏膜修复因子黏蛋白5AC(MUC5AC)和表皮生长因子(EGF)表达,应用ELISA法检测血清白细胞介素(IL-6、IL-1β)和肿瘤坏死因子α(TNF-α)水平,采用16S rDNA高通量测序法检测肠道菌群多样性,使用Western Blot法检测肠组织Toll样受体4/核因子κB(TLR4/NF-κB)信号通路蛋白表达。结果与模型组比较,NaB低剂量组、NaB高剂量组和奥美拉唑组大鼠胃溃疡面积、血清IL-6、IL-1β及TNF-α水平、变形菌门相对丰度、肠组织TLR4、NF-κB p65表达量均减少(均P<0.05),胃黏膜组织MUC5AC、EGF mRNA、肠道菌群Shannon指数、拟杆菌门相对丰度及核因子κB抑制因子α(IκBα)表达量均升高(均P<0.05),NaB高剂量组上述指标与奥美拉唑组比较,差异均无统计学意义(均P>0.05)。结论NaB可显著抑制大鼠胃溃疡,促进胃黏膜修复,改善肠道菌群紊乱,其机制可能与调节TLR4/NF-κB信号通路减轻炎症反应有关。

Objective To explore the effects of sodium butyrate(NaB)on intestinal inflammation and composition of intestinal flora in rats with gastric ulcer so as to provide experimental evidence in the treatment of gastric ulcer with NaB.Methods SPF-level SD rats(6-8 weeks old,body mass:180-240 g)were randomly divided into normal group,model group,low-dose NaB group,high-dose NaB group and omeprazole group,8 cases in each group.The models of rats with gastric ulcer were constructed by hydrochloric acid+ethanol method.The rats in low-dose NaB group,high-dose NaB group and omeprazole group were given intragastric administration of 200 mg/kg NaB solution,400 mg/kg NaB solution and 20 mg/kg Omeprazole solution(once/d for 5 d),respectively.The gastric injury was evaluated,pathological changes of gastric mucosa were observed,the expressions of mucin 5AC(MUC5AC)and epidermal growth factor(EGF)in gastric mucosa were detected with fluorescence quantitative PCR,levels of serum interleukins(IL-6,IL-1β)and tumor necrosis factorα(TNF-α)were detected with ELISA,diversity of intestinal flora was detected by 16S rDNA high-throughput sequencing method,and expressions of Toll-like receptor 4/nuclear factorκB(TLR4/NF-κB)signaling pathway related proteins were detected with Western blot.Results Compared with model group,gastric ulcer area,levels of serum IL-6,IL-1βand TNF-α,relative abundance of Proteobacteria,and expressions of TLR4 and NF-κB p65 in intestinal tissues were decreased(all P<0.05),while mRNA levels of MUC5AC and EGF,Shannon index of intestinal flora,relative abundance of Bacteroides and expression of nuclear factorκB inhibitorα(IκBα)were increased in low-dose NaB group,high-dose NaB group and omeprazole group(all P<0.05).There were no significant difference in the above indexes between high-dose NaB group and omeprazole group(all P>0.05).Conclusion NaB can significantly inhibit gastric ulcer,promote repair of gastric mucosa and improve intestinal flora disorders in rats,and its mechanism may be related to regulating TLR4/NF-κB signaling pathways and relieving inflammatory response.