膳食纤维肠内营养对全肠道缺血再灌注大鼠肠屏障功能的影响

目的：通过建立大鼠全肠道缺血再灌注模型,探讨膳食纤维肠内营养对肠屏障功能的影响。方法：将实验大鼠随机分成4组,每组10只。第1组为对照组,第2组为缺血再灌注组（I/R组）,该两组为术后24h取材。第3组为普通肠内营养组（EN组）,第4组为膳食纤维肠内营养组（FEN组）,营养支持7d后取材。上述4组均行回、结肠形态学检查,细菌及内毒素移位、结肠固有层淋巴细胞分布检测,用循环D-乳酸法测定肠道通透性。结果：I/R组大鼠回、结肠黏膜萎缩,腺体稀疏,黏膜下层水肿、出血。FEN组肠黏膜形态学变化好于EN组。I/R组细菌移位率、血浆D-乳酸、血浆内毒素显著高于对照组;FEN组D-乳酸、内毒素水平低于EN组。I/R组结肠固有层CD4＋、CD8＋T淋巴细胞显著低于其余各组。FEN组CD4＋、CD8＋T淋巴细胞较EN组增多。结论：添加膳食纤维的肠内营养在维护肠黏膜屏障、改善肠道免疫功能、防止细菌及内毒素移位方面作用优于单纯肠内营养。膳食纤维能提高结肠局部免疫功能。

The influences of enteral nutrition with dietary fiber on intestinal barrier function in rats with entire gut ischemia/reperfusion injury

Objective To explore the influences of enteral nutrition with dietary fiber on intestinal barrier function via constructing a rat model of entire gut ischemia/reperfusion (I/R) injury. Methods Forty rats were randomized to control group, I/R group, enteral nutrition (EN) group, or dietary fiber nutrition (FEN) group (10 for each group). The samples of the gut were obtained for examination. The morphology of ileum and colon, bacterial and endotoxic shift, and distribution of lymphocytes in the colon were detected. The permeability of intestinal mucosa was measured by circulatory D-lactate. Results The ileocolonic mucosa was shrunk, glands became sparse, and submucosal edema and bleeding occurred in I/R group, while fewer changes in the intestinal morphology were found in FEN group than EN group. The rate of bacterial shift and the levels of D-lactate and endotoxin in I/R group were significantly higher than those in the control group, but those of D-lactate and endotoxin were lower in FEN group than EN group. The number of T-lymphocytes CD4 and CD8 in the lamina propria of colon was remarkably lower in I/R group than that in the other groups while it was significantly elevated in FEN group than in EN group. Conclusions Enteral nutrition with dietary fiber is superior to that without dietary fiber in maintaining intestinal barrier, improving intestinal immune function, and preventing bacteria and endotoxin from shifting. Dietary fiber can enhance the local immune function of colon.