摘要：目的：通过探究老年痴呆模式小鼠的小肠菌群结构的变化，分析老年痴呆症的发生与小肠菌群结构的关系，为老年痴呆症的预防、治疗提供依据。方法：通过酚-氯仿抽提法从AD模式小鼠小肠内容物中提取微生物基因组DNA，通过PCR扩增及DGGE电泳研究其与健康小鼠小肠内容物中微生物群落的不同。结果：采用该方法成功地扩增出16S rRNA V3区230bp的片段，经DGGE方法后用Bionumerics软件分析表明AD模式小鼠组与健康小鼠组小肠内容物菌群条带数、多样性指数、丰富度指数、均匀度指数与优势度指数还有相似度指数都存在显著差异。结论：基于16S rRNA V3区的PCR-DGGE技术可以分析研究肠道微生物结构，对肠道微生物初筛的结果表明老年痴呆模式小鼠的小肠菌群与健康小鼠的小肠菌群结构存在差异，这种差异可以为老年痴呆症的治疗提供理论依据。

关键词：老年痴呆; 小肠; 微生物; DNA; PCR; DGGE电泳

Abstract: Objective: Study on the change of bacterial community in Alzheimer’s sufferers of the small intestine, Analysis the relationship of the occurrence of Alzheimer's Disease and intestinal microbiota structure，establish the theoretical basis for preventing Alzheimer’s Disease. Methods: through phenolic chloroform extraction from Alzheimer's disease patterns of mice intestine contents, microbial genomic DNA by PCR amplification and DGGE electrophoresis research Alzheimer's mice with the normal mice intestine of different microbial community. Results: the method can amplify 16S rRNA V3 specific regions of the 230bp fragment successfully．The DGGE method Bionumerics after software analysis shows that the AD mode groups of mice were and health groups of mice were small intestinal content channel number, diversity index, richness index, evenness index and the dominance index and similarity index are significant differences. Conclusionthe: the PCR—DGGE technology based on 16S r RNA V3 region can be applied in the study of intestinal microbial diversity，for intestinal microbial screening results showed that senile dementia model mouse small intestinal microbiota structure and healthy mice intestinal flora structure are different，and through improved diet for prevention of Alzheimer's Disease．

Key words：Alzheimer；Intestine；Microbiota；PCR；DGGE