微生物群落应用于法医学个体识别的探索研究

One of the cutting-edge of science research for forensic genetics is Individual identification using bacterial communities. The results of the Human Microbiome Project (HMP) showed that the microbial community at human body (surface) presented significant individual differences in the same site, and can be transferred to the surfaces through touch, which suggested microbial community has good potential to be applied to forensic individual identification. At present, the bacterial communities limited by lack of the domestic and international systematic studies, microbial community has not yet been applied to forensic science application. The development of next-generation sequencing technology opened up a new prospect for microbial community screening. In this study, we plan to collect a variety of samples including human skin (hair), saliva, feces and vaginal secretions, together with corresponding contact samples: 1) Screening bacterial communities using next-generation sequencing technology, detecting and then comparing with these two microbial communities, to explore and find such microbial communities which had important significance for forensic identification, had obvious difference between different individuals and could be detected at surfaces after touching; 2) establishing a low-cost T-RFLP, PCR-DGGE method, which could be suitable to large sample detection; 3) searching microbial detection marks with high stability and suitable for forensic identification. We will try to development a rapid, effective and useful comparison method for microbial communities from human body and the surfaces through touch, and wish to provide scientific basis for the application of microbial community in forensic science.

微生物群落进行个体识别是法医物证学的研究前沿之一，人类微生物组计划的研究成果揭示了人体内（表）的微生物群落具有的个体间同一部位的差异性，并且可通过接触转移到物体表面，使其可应用于法医学个体识别。目前，国内外相关的研究缺乏，尚未应用于法医学实践。二代测序技术的发展为微生物群落的筛选提供了新的前景。本课题拟通过采集人体皮肤（毛发）、唾液、粪便和阴道分泌物样本及其对应的接触物样本：1）利用高通量二代测序技术筛选，通过检测比对两者的微生物群落，探索和寻找具有法医学鉴定意义的,在人类不同个体中具有差异性的微生物群落；2)建立低成本的T-RFLP、PCR-DGGE方法可用于大样本量的微生物群落检测方案；3）通过法医学应用评估，寻找具有高稳定性的、适用于法医学的微生物检测标记。通过上述方案建立快速、有效的人体与其接触物法医学微生物群落应用比对方案，以期为微生物群落在法医学领域个体识别的应用提供科学依据。

个人识别是法医物证学的重要任务之一，是用来揭示个体身份，是侦查破案的重要环节。由于人体内（表）的微生物群落可能通过接触转移到物体表面，微生物群落可能具有的个体部位差异性为其在法医学领域的个体识别应用提供了可能。本项目通过采集人体皮肤（毛发）、唾液、粪便和阴道分泌物样本及其对应的接触物样本：1）在微生物基因组中寻找候选的微生物标记，分别运用T-RFLP、HRM、SBE检测技术研究人体微生物群落多样性及个体差异性。我们在链球菌和韦荣氏球菌中共筛选出3个特异性位点，基于SBE方法建立了CE平台微生物16S rRNA基因分析体系并成功对不同个体进行分型；2）运用二代测序技术，深入分析了唾液和口腔黏膜的微生物群落组成分析，基于微生物群落组成差异性分析，运用机器学习可将两者进行区分，为后续的同一认定的模拟样本研究提供了实验基础，同时补充了法医细胞鉴定的研究内容。3）基于肠道微生物的群落组成研究，观察到在不同的BMI组的群落组成差异，基于这些差异，通过分类分析可以将不同BMI组的个体进行区分并建立适用于个体的体型预测模型。为微生物群落在法医学领域个人识别的应用提供新的技术方法。