摘要：
目的 比较分析 WHBE 兔和日本大耳白(Japanese white rabbit, JW)兔腹泻型肠易激综合征(irritable bowel syndrome,IBS)模型肠道菌群的差异性.方法 WHBE兔和JW兔各16只,按品系随机分为两组,即正常对照(NC)组和IBS模型组,每组8只.采用湿热应激复合番泻叶方法建立腹泻型IBS兔模型,观察实验兔的腹围指数、粪便含水量、结肠转运功能,处死后分别取结肠组织和结肠内容物进行病理组织学观察和肠道菌群多样性分析.结果 与NC组比,IBS模型兔均出现腹围指数和粪便含水量增加,结肠转运时间缩短,但结肠组织未见病理性改变;同时IBS模型兔Shannon指数和Chao1指数均显著下降(P<0.05).根据OTU分类分析的结果,厚壁菌门和拟杆菌门为兔肠道菌群的绝对优势菌群.与NC组比较,WHBE兔IBS模型组厚壁菌门、疣微菌门、绿弯菌门、Akk菌属、链球菌属均明显下降(P<0.05, P <0.01),拟杆菌门和 rc4-4菌属丰度显著上升(P <0.05, P <0.01);而JW兔IBS模型组优杆菌属和罕见小球菌属均显著上升(P<0.05),乳酸杆菌属、粪杆菌属、韦荣球菌属和链球菌属均显著下降(P<0.05).与JW 兔NC组比,WHBE兔NC组厚壁菌门、Odoribacter菌属、韦荣球菌属、链球菌属、颤螺旋菌属、Pseudoflavonifractor菌属较低(P<0.05,P<0.01),拟杆菌门、疣微菌门、优杆菌属、粪杆菌属、Akk菌属较高(P<0.05,P<0.01).与JW兔IBS模型组比,WHBE兔IBS模型rc4-4菌属、粪杆菌属、梭菌属的丰度较高(P<0.05,P<0.01),而厚壁菌门、多尔氏菌属、粪球菌属和罕见小球菌属的丰度则较低(P<0.05,P<0.01).结论 IBS模型兔存在肠道菌群失调,导致菌群多样性降低;WHBE兔和JW兔IBS模型肠道菌群变化均具有其自身的特点,且具有明显的差异性.%Objective To compare the differences in the intestinal microflora of WHBE rabbit and JW rabbit models of diarrhea-predominant irritable bowel syndrome(IBS). Methods 16 WHBE rabbits and 16 JW rabbits were randomly divided into normal control(NC)group and IBS model group, respectively(n=8). The diarrhea-predominant IBS model was established by wet-heat stress combined with intragastric gavage of senna decoction. The abdominal circumference index,water content of feces and colonic transit function were observed. After sacrifice,colon tissue samples were taken for histopathological examination and colon contents for intestinal flora diversity analysis. Results Compared with the NC group,the IBS model rabbits showed an increased abdominal circumference index and fecal water content,and a shortened colon transit time, but no obvious pathological changes were observed in the colon tissues. Meanwhile, the Shannon index and Chao1 index of IBS model rabbits were significantly decreased(P<0.05). According to the result of OTU classification analysis,Firmicutes and Bacteroidetes are the dominant bacteria in the intestinal microflora of rabbits. Compared with the NC group, the Firmicutes, Verrucomicrobia, Chloroflexi, Akkermansia, and Streptococcus in the WHBE rabbit IBS model group were significantly reduced(P < 0.05, P < 0.01), while Bacteroidetes and rc4-4 significantly increased(P < 0.05, P < 0.01). However, in the JW rabbit IBS model group, Eubacterium and Subdoligranulum were significantly increased(P< 0.05),while Lactobacillus,Coprobacter,Veillonella and Streptococcus were markedly decreased(P<0.05). Compared with the JW rabbit NC group,the abundance of Firmicutes,Odoribacter, Veillonella,Streptococcus,Oscillospira and Pseudoflavonifractor were significantly decreased(P<0.05, P<0.01), but Bacteroidetes,Verrucomicrobia,Eubacterium,Akkermansia and Coprobacter were significantly increased(P<0.05,P<0.01)in the WHBE rabbit NC group. Compared with the JW rabbit IBS model group, the abundance of rc4-4, Bacteroidetes,Coprobacter and Clostridium were significantly higher(P < 0.05, P < 0.01), while the Firmicutes, Dorea, Coprococcus and Subdoligranulum were significantly lower(P <0.05)in the WHBE rabbit IBS model group. Conclusions There is an intestinal microflora imbalance in rabbits with IBS, resulting in a decrease of microflora diversity. The changes of intestinal microflora in the WHBE rabbits and JW rabbits with IBS have their own characteristics, and have apparent differences.
