甘草多糖对ETEC诱导断奶腹泻仔猪肠道损伤及肠道菌群的调控机制  

Regulatory mechanism of glycyrrhiza polysaccharide on intestinal damage and intestinal flora in enterotoxigenic Escherichia coli-induced weaning diarrhea piglets

作　　者：曾雯玉 肖乐 刘峻源 韩雯珏 汪芹 刘彦泠 范誉 肖雄[1] 王自力 ZENG Wenyu;XIAO Le;LIU Junyuan;HAN Wenjue;WANG Qin;LIU Yanling;FAN Yu;XIAO Xiong;WANG Zili(College of Veterinary Medicine,Southwest University,Chongqing400715,China;Center for Veterinary Sciences,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]西南大学动物医学院,重庆北碚400715 [2]浙江大学动物医学中心,浙江杭州310058

出　　处：《中国兽医学报》2024年第4期740-747,833,共9页Chinese Journal of Veterinary Science

基　　金：国家自然科学基金资助项目(31872507)。

摘　　要：将24头21日龄断奶仔猪随机分为空白组(Con)、模型组(Mod)和甘草多糖组(GP),连续14d给GP组灌服甘草多糖水溶液(1mL/kg,10g/L),其余组灌服等量无菌水,第15天给Mod组、GP组仔猪按1mL/kg连续3d灌服1011 CFU/mL的产肠毒素大肠杆菌(enterotoxigenic Escherichia coli,ETEC)菌液,GP组继续灌服甘草多糖水溶液。分别记录各组仔猪腹泻评分、HE法检测肠道组织病理学变化、实时荧光定量PCR检测肠道组织IL-1β、IL-6、IL-8 mRNA水平、微生物宏基因组学分析肠道菌群变化情况、Western blot检测肠道组织NF-κB/MAPK信号通路相关蛋白水平。结果显示,与Con组相比,ETEC感染后Mod组腹泻评分极显著升高(P<0.01),肠道组织结构破坏,大量肠绒毛脱落,V/C值极显著下降(P<0.01),炎性因子IL-1β、IL-6和IL-8mRNA水平极显著升高(P<0.01),变形菌门极显著上调(P<0.01),厚壁菌门极显著下调(P<0.01),乳酸菌属下调,梭菌属上调,肠道组织p-JNK/JNK、p-ERK/ERK、p-p38/p38、p-p65/p65和p-IκBα/IκBα比值极显著升高(P<0.01);与Mod组相比,GP组仔猪腹泻评分极显著降低(P<0.01),肠道结构较完整,仅有少量肠绒毛脱落,V/C值极显著升高(P<0.01),炎性因子IL-6和IL-8 mRNA水平显著或极显著降低(P<0.05或P<0.01),变形菌门极显著下调(P<0.01),厚壁菌门极显著上调(P<0.01),乳酸菌属上调,梭菌属下调,肠道组织p-JNK/JNK、p-ERK/ERK、p-p38/p38、p-p65/p65和p-IκBα/IκBα比值显著或极显著降低(P<0.05或P<0.01)。微生物组学筛选出各组可能的标记物种分别为Con组的Lactobacillus、Mod组的Fusobacterium、GP组的Rothia和Eubacterium。结果表明,甘草多糖可有效缓解ETEC诱导的断奶仔猪腹泻,改善ETEC感染引起的肠道菌群紊乱,提高有益菌丰度,降低有害菌丰度,并通过抑制NF-κB/MAPK信号通路的激活,缓解ETEC诱导的肠道炎性损伤。The aim of this study was to investigate the regulation and mechanism of glycyrrhiza polysaccharides in enterotoxigenic Escherichia coli(ETEC)-induced diarrhea in weaned piglets.Twenty-four piglets weaned at 21days of age were randomly divided into the control group(Con),the model group(Mod),and the glycyrrhiza polysaccharide group(GP).The GP group was given glycyrrhiza polysaccharide aqueous solution(1mL/kg,10g/L)for 14days,and the other groups were given the same amount of sterile water.On day 15,piglets in the Mod and GP groups were given 1011 CFU/mL of ETEC bacterial solution at 1mL/kg for 3consecutive days,while the GP group continued to receive an aqueous glycyrrhiza polysaccharide solution.The diarrhea score of the piglets in each group was recorded.The intestinal histopathological changes were detected by HE staining.By real-time quantitative PCR,mRNA levels of IL-1,IL-6,and IL-8in intestinal tissues were detected.The intestinal flora changes were analyzed by microbial metagenomics.The levels of NF-κB/MAPK signaling pathway-related proteins in intestinal tissues were measured by Western blot.The results showed that,after ETEC infection,the diarrhea score in the Mod group was significantly increased(P<0.01)compared to the Con group.The intestinal tissue structure was destroyed in the Mod group.The V/C value was significantly decreased(P<0.01),and the mRNA levels of inflammatory factors IL-1β,IL-6,and IL-8were significantly increased(P<0.01)in the Mod group compared with the Con group.Proteobacteria were significantly increased(P<0.01),and firmicutes were significantly decreased(P<0.01)in the Mod group compared to the Con group.Lactobacillus was decreased,Fusobacterium was increased,and the ratio of p-JNK/JNK,p-ERK/ERK,p-p38/p38,p-p65/p65,and p-IκBα/IκBαin intestinal tissue was significantly increased(P<0.01)in the Mod group compared to the Con group.Compared with the Mod group,the diarrhea score of piglets in the GP group was significantly decreased(P<0.01).Only a small amount of intestinal villi she

关 键 词：产肠毒素大肠杆菌 断奶仔猪腹泻 肠道菌群 NF-κB/MAPK信号通路 

分 类 号：S852.3[农业科学—基础兽医学]