摘要：人体内庞大的微生物群体对人体有着巨大的影响。本文基于此对老年痴呆症的发生与胃肠道菌群的关系进行了研究。针对8例老年痴呆症模式小鼠与8例健康小鼠的胃容物样本进行预处理后，提取样本菌群基因组DNA，并进行16S rRNA v3区片段PCR扩增，扩增产物用变性梯度凝胶电泳法(DGGE)检测分析。结果发现，老年痴呆症模式小鼠组与健康小鼠组的胃肠道菌群相似性指数仅为0.4左右。实验结果对研究老年痴呆症的发病机理及并发症治疗有重要意义，为预防老年痴呆症的发生奠定理论基础。

关键词：胃肠道菌群；16S rRNA；PCR；变性梯度凝胶电泳

Abstract：The microbial communities great affect human physiology. Based on it,the relationship of the occurrence of Alzheimer's Disease and intestinal microbiota structure were investigated. In this study, stomach samples of 8 Alzheimer's Disease model mice and 8 healthy mice were collected. Total bacteria genomic DNA was extracted from the fecal samples after pre-treatment.For 16S r RNA V3 region PCR amplification，and PCR products were detected and analyzed by denaturing gradient gel electrophoresis(DGGE)．Comparing the stomach content of Alzheimer's Disease model mice group and health mice groups,significant differences were found as shown in similarity index is only about 0.4. The experimental conclusion can be applied in the study of intestinal microbial diversity，which may be of significance for the research of diabetes pathogenesis, establish the theoretical basis for preventing Alzheimer's Disease.

Key words：stomach microbiota structure；16S r RNA；PCR；DGGE