膳食纤维肠内营养对大鼠急性重症胰腺炎肠屏障功能的影响

Influences of dietary fiber enteral nutrition on the barrier function of the gut in rats with severe acute pancreatitis

目的探讨早期添加膳食纤维(dietary fiber,DF)、肠内营养(enteral nutrion,EN)对急性重症胰腺炎(severe acute pancreatitis,SAP)大鼠肠屏障功能的影响。方法SD大鼠32只,随机分成4组(n=8):SAP组(A组),EN组(B组),膳食纤维肠内营养(fiber enteral nutrion,FEN)组(C组)和对照组即假手术组(D组)。采用逆行胰胆管注射3.5%牛磺胆酸钠溶液制成重症胰腺炎大鼠模型。A组和D组术后36 h开始自由饮葡萄糖盐水;C组和B组术后36 h开始空肠营养管分次注射肠内营养液。5 d后再次麻醉大鼠,收集组织及血液标本;检测指标包括细菌移位率、胰腺病理评分、结肠组织形态学变化、血浆D-乳酸以及小肠黏膜固有层CD4+,CD8+和CD4+/CD8+比值等。结果SAP大鼠结肠黏膜萎缩,黏膜腺体稀疏。FEN组结肠黏膜形态变化好于EN组。FEN组细菌培养阳性率明显低于SAP组。FEN组血浆D-乳酸水平明显低于EN组。FEN组与EN组比较,胰腺病理学评分、CD4+、CD8+淋巴细胞数和CD4+/CD8+比值差异无统计学意义。结论添加DF的EN在维护SAP肠黏膜屏障、改善肠道免疫功能、防止细菌易位方面作用优于单纯EN。DF尚不能提高小肠局部免疫功能。

Objective To evaluate the influence of early dietary fiber （DF） enteral nutrition （EN） on the intestinal barrier function and bacterial translocation in severe acute pancreatitis （SAP） in rats. Methods 32 SD rats were randomized into four groups with eight animals in each group： SAP group, enteral nutrition （EN） group, dietary fiber nutrition （FEN） group and control group （sham）. SAP was induced by retrograde injection with 3.5% sodium taurocholate into the biliopancreatic duct; and the catheter was introduced into the jejunum via a gastrestomy in all rats. Drinking glucose saline freely was initiated 36 hours latex in SAP group and control group; the nutrient was initiated 36 hours later in EN group and FEN group by fractional injection into the jejunum; and the rats were sacrificed in 5 days, tissue and blood samples were collected for further study. Criteria indicating the outcome were： bacterial translocation rate （culture of the samples of blood, mesenteric lymph node, pancreas and liver）, histological score of the pancreas, the intestinal morphology and the plasma level of D-lactate. The numbers of CD4^＋ and CD4^＋ lymphocyte in the intestinal lamina propria were analyzed. The CD4^＋/CD8^＋ ratio was calculated. Results There was serious damage in intestinal tissue of SAP group with colon mucosa atrophy and gland rarefaction. FEN group was supexior to EN group in the colon morphology. The plasma level of D-lactate was significantly lower in FEN group than that in EN group. The was no difference in the histological score of the pancreas, the numbers of CD4^＋ and CD8^＋ lymphocyte and the CD4^＋/CD8^＋ ratio. Conclusion The common enteral nutrition contained dietary fiber in safeguarding gut immune barrier function, and in preventing bacterial translocation is superior to the enteral nutrition alone in SAP. The dietary fiber cannot improve local immune function of small intestine.