摘要：为了探究老年痴呆症与盲肠菌群结构的关系，采集盲肠菌群，去除杂质、分离菌体、采用酚/氟仿法抽提细菌基因组DNA。并对其中16S rRNA V3可变区进行聚合酶链式反应(PCR)扩增和变性梯度凝胶电泳（DGGE)测定。用Bionumerics软件对DGGE分子指纹图谱进行菌群结构相似性分析。实验结果表明，采用该方法成功地扩增出16S rRNA V3区片段，大小约为230bp。DGGE分子指纹图谱结果表明，正常小鼠之间的菌群最高相似性为0.88。患老年痴呆症的小鼠的盲肠菌群的最高相似性为0.88，正常小鼠的盲肠菌群与患老年痴呆症的盲肠菌群相似性最高为0.67。即患老年痴呆症的小鼠盲肠菌群结构与正常小鼠有显著差异。

关键词：老年痴呆症；盲肠；16S rRNA；菌群结构

Abstract : In order to research the relationship of senile dementia and cecal flora structure， acquisition of cecal flora Impurities were eliminated and the bacteria was separated．The total microbial genome DNA of each sample was extracted by phenol—chloroform，V3 regions of 16S rRNA was amplified with PCR，and PCR products were analyzed by DGGE．The similarity of bacteria structure was analyzed with Bionumerics．The result showed that V3 regions of 1 6S rRNA was extracted，230 bp．DGGE suggested that the highest similarity was 0.88 in normal mice．That of senile dementia mice was 0.88，and that of normal mice and senile dementia mice Was 0.67．Therefore，there is some significantly different between senile dementia mice and normal mice.

Key Words: senile dementia; cecal; 16S rDNA; bacteria colony structure