益生菌联合肠内营养对腹腔感染大鼠肠微生态及屏障功能的影响

目的探讨肠内肠外营养与经肠道补充益生菌对腹腔感染大鼠肠道微生态及肠屏障功能的影响。方法21只SD大鼠随机分为3组(每组7只),分别给予肠外营养(PN组)、肠外加肠内营养(PN加EN组)和肠外、肠内营养加益生菌(益生菌组)。3组营养供给为等热、等氮量。于第6天处死大鼠,取其盲肠内容物作厌氧菌培养,采用随机扩增多态性DNA技术作菌种DNA指纹图谱分析;采用免疫组织化学方法测定其末段回肠和结肠的跨膜结合蛋白及肠上皮浆细胞免疫球蛋白(IgA)表达水平;取腔静脉血及肺、肝、肠系膜淋巴组织匀浆后作细菌培养,测细菌易位率;采用鲎试剂法检测门静脉血内毒素含量。结果(1)益生菌组及PN加EN组各种菌种的数量均较PN组增多(P<0.05)。PN组细菌DNA指纹图谱条带明显减少,且出现明显异常条带,其他两组大鼠肠道内优势菌群的基因条带与正常大鼠具有较高的一致性。(2)PN加EN组和益生菌组小肠和结直肠跨膜结合蛋白及IgA表达明显高于PN组(P<0.05及P<0.01),且益生菌组跨膜结合蛋白的表达高于PN加EN组(P<0.05);PN加EN组的小肠和益生菌组结直肠IgA的表达明显高于PN组(P<0.01)。(3)PN加EN组和益生菌组血、肺、肝、肠系膜淋巴组织的细菌易位率和内毒素水平均低于PN组(P<0.05),前两组之间差异无统计学意义。结论益生菌联合EN能增加肠上皮跨膜结合蛋白IgA表达,改善肠道微生态,从而保护肠黏膜屏障、减少细菌易位。

Influences of enteral nutrition combined with probiotics on the gut microecology and barrier function of the rats with abdominal infection

Objective To investigate the influences of enteral nutri ti on(EN),parenteral nutrition(PN) and probiotics supplement on the intestinal micr oecology,and barrier function of the rats with abdominal infection. Methods Twen ty-one Sprague-Dawley( SD) rats with abdominal infection were randomly di vided into three groups,and received PN(PN group,n=7),PN+ EN(PN+ EN group,n=7) or PN+ EN+ probiotics (probiotics group,n=7) respectively with isonitrogen an d isocaloric nutrition. The rats were sacrificed after six days. The feces in ce cum were cultured for anaerobic bacterial growth and DNA fingerprint spectrum wa s analyzed by randomly amplified polymorphic DNA technique. The transmembrane bi nding protein (occludin) and IgA levels in colon and terminal ileum were detecte d by immunohistochemistry method. The bacterial translocation rate and endotoxin level were also measured. Results The germ numbers of different species were bo th higher in PN+ EN and probiotic group than those in PN group. The bands of DN A fingerprint spectrum were significantly decreased in PN group,but the bands in both PN+ EN group and probiotic group were similar to that in the normal rats. The expression levels of occludin and IgA in the intestine and colorectum were higher in both PN+ EN group and probiotic group compared with those of PN group ( P< 0.05,P< 0.01,respectively) ,the expression level of occludin was higher in probiotic group than that in PN+ EN group(P< 0.05). The overall ba cterial translocation rates and endotoxin levels were significantly reduced in b oth probiotic and PN+ EN group( P< 0.05) ,but there was no difference between probiotic group and EN group. Conclusion EN combined with probiotics can increa se occluding and IgA expressions,improve the intestinal microecology,maintain th e gut barrier function,and decrease the incidence of gut bacterial translocation .