原位肝移植大鼠肠道微生态状况研究

The change of intestinal microecology in rats after orthotopic liver transplantation

目的探讨肝移植术后大鼠肠道微生态的变化。方法将雄性Brown-Norway（BN）大鼠40只随机分成肝移植组（BN-BN，n=16，共8对）、模拟移植组（n=8）、假手术组（n=8）和对照组（n=8），24h后处死，分析肠道菌群构成、回肠末端超微结构变化、血浆内毒素水平以及细菌易位至肝、脾、肾和肠系膜淋巴结的比例。结果肝移植术后24h存在明显的肠道菌群紊乱，表现为肠杆菌科细菌和肠球菌数量增加（P〈0．05），乳杆菌和双歧杆菌数量下降（P〈0、05），移植组与模拟移植组存在肠黏膜上皮细胞微绒毛的损伤；肝移植组血浆内毒素水平升高（P〈0．01），细菌易位至肝脏、脾脏和肠系膜淋巴结的阳性率增加（P值均〈0、05）；与模拟移植组比较，肝移植组细菌易位至肝脏的阳性率增加（P〈0．05）。结论肝移植术后存在一定程度的肠道微生态紊乱和肠道屏障功能损伤，可能与肝移植手术过程中所经历的缺血再灌注过程有关。

Objective To investigate the intestinal microflora status and bacterial translocation in rats after liver transplantation. Methods Male Brown-Norway （ BN ） rats were randomly divided into 4 groups ： groupⅠ（ n = 8） for liver transplantation ; group Ⅱ（ n = 8 ） for simulated liver transplantation ; group Ⅲ （ n = 8 ） for sham operation and group Ⅳ （ n = 8 ） for normal group. Caecal bacterial counts, plasma endotoxin, intestinal mucosal ultrastructure and bacterial translocation to liver, spleen, kidney, and mesenteric lymph node were studied 24 h after surgery. Results The numbers of Bifidobacterium and Lactobacillus per gram of wet feces were significantly decreased in group Ⅰ compare with those in the group Ⅲ and group Ⅳ, while Enterobacteriaceae and Enterococus counts were increased markedly compare with those in the group Ⅲ and group Ⅳ, but no different was found between group Ⅰ and group Ⅱ. Impaired intestinal mucosa integrity were found in the group Ⅰ and group Ⅱ. In group Ⅰ , the levels of plasma endotoxin increased after the transplantation when compare with group Ⅲ and group Ⅳ. Increased incidence of bacterial translocation to liver, spleen and mesenteric lymph node were also observed after the transplantation（ compare with those in the group Ⅳ ,P 〈0. 01 ;compare with those in the group Ⅲ ,P 〈0. 01 ,P 〈0. 01 ,P 〈0. 05 ,separately）. The increased rate of the bacterial translocation in liver was also found in transplantation group as compare with group Ⅱ （ P 〈 0. 05 ）. Conclusions Liver transplantation may lead to disturbance of intestinal microflora and impairment of intestinal mucosal barrier function, and this dysfunction might be caused by the process of intestinal isehemia-reperfusion injury in transplantation.