膳食诱导肥胖大鼠模型的肠道菌群结构及其特异分子标识物

目的通过对膳食诱导肥胖（Diet Induced Obesity，DIO）大鼠与健康对照组大鼠的肠道菌群结构的分析比较，寻找造成2组大鼠菌群结构差异的分子标识物，探讨肠道菌群的组成和结构与宿主肥胖之间的关系。方法ERIC—PCR结合Southern-blot得到肠道菌群基因组指纹图谱，利用Southem-blot与多元统计方法（PCA、PLS等）找出差异条带，回收差异条带进行测序，根据序列设计特异性引物，以定量PCR法对结果进行验证。结果ERIC-PCR图谱表明膳食诱导肥胖大鼠在肠道菌群结构上与正常大鼠存在着较大的区别；根据杂交结果找到一段基因组DNA片段为膳食诱导肥胖大鼠组所特有，定量分析表明该DNA片段在2组大鼠间区别明显。结论膳食诱导肥胖大鼠所特有的一段基因组DNA片段可作为肥胖大鼠肠道的特征分子标识物，该标识物有望用于膳食诱导肥胖的机制研究中。

Intestinal microbiota structure of diet-induced obesity rats and its specific molecular marker

Objective To find out a molecular marker which could differentiate the diet-induced-obesity （DIO） rats and control rats,and probe into the relationship between microbiota structure and obesity. Method ERIC-PCR combined with Southern-blot were applied to obtain fingerprint profiles, and then the band that was unique to the DIO group was sequenced. Specific primers were designed based on the sequenced DNA fragment, and used for quantitative PCR to verify the distribution of this DNA fragment in microflora of the two animal groups. Result This experiment indicated the differenee of microbiota structure between the DIO and control rats. Besides,a genomic DNA fragmem was detected only in DIO group, and the discrepancy between the two groups was found by quantitative PCR to be significant. Conclusion A genom- ic DNA fragment, which was unique to DIO group and was a key differentiator to distinguish normal rats, could be used as a molecular marker to study the mechanism of diet-induced-obesity.