泌尿系结石成分类型与肠道微生物群宏基因组关联性研究

The assessment and characterization of intestinal microbiota has become an important area of human disease researches,such as obesity,diabetes ,which had been proved correlate with intestinal microbiota by metagenomics.Urolithiasis is the results of interaction among genetics,climate,diet,which is characterized with complex etiology and various composition.In theory,the absorption of diet and stone formation risk factors were influenced by intestinal microbiota.Previous studies found that the bacteria with oxalate-degrading potency in gut correlate with hyperoxaluria and oxalate calcium stones formation.So the relationship study between gut microbiota and urolithiasis is worth exploring.The applicant had isolated oxalobacter formigenes from Chinese and cloned key functional genes,as well as constructed lentiviral vector then made transgenic liver stem cell get potency of oxalate-degrading potency. But the association study of gut microbiome and urolithiasis compositions from overall perspective was not reported yet. The 10 urolithiasis patients with the most common compositions will be recruited in the study,then the potential relationship between the intestinal microbiota and functional gene and the stone composition from the metagenome-wide level,stone composition was analyzed by infrared spectrometer,explore the specific microorganisms and functional genes corresponding to different composition types stones.The results will provide new sights for the etiology of urolithiasis.

肠道微生物群特性评估已成为人体疾病病因学的重要研究领域，利用宏基因组技术已发现肥胖、糖尿病等常见代谢疾病与某些肠道微生物群密切相关。尿石成分多样，成石机理复杂，是遗传、气候、饮食等内外因素共同作用的结果。理论上肠道微生物群会影响饮食吸收代谢乃至成石风险，现有研究已发现肠道中一些具有草酸代谢功能的菌群影响草酸吸收进而干扰草酸钙结石形成。尿石和肠道微生物关系值得探讨。申请者团队已分离培养出中国人肠道产甲酸草酸杆菌并克隆功能基因，构建慢病毒转染细胞后获得草酸分解功能。但未见报道从整体视角探讨肠道微生物群及其功能基因与不同成分泌尿系结石的关联性。基于前期工作本课题拟通过宏基因组技术按全基因组测序和16S rDNA测序两种策略研究10种常见成分类型尿石症患者粪便中微生物群，探寻不同成分结石类型关联的特异性微生物群和功能基因，为肠道微生物群与尿石病因关系探索提供新思路。

肠道微生物群特性评估已成为人体疾病病因学的重要研究领域，利用宏基因组技术已发现肥胖、糖尿病等常见代谢疾病与某些肠道微生物群密切相关。目前研究多认为泌尿系结石是一种代谢相关的疾病，其结石成分多样，成石机理复杂，是遗传、气候、饮食等内外因素共同作用的结果。各种原因导致的高草酸尿、高钙尿、高尿酸尿、低枸橼酸尿和其他尿液异常均是重要的成石危险因素。理论上肠道微生物群会影响饮食吸收代谢乃至成石风险，我们前期的研究已发现肠道内存在可代谢草酸并对尿草酸排泄产生影响的菌群。申请者团队将草酸脱羧酶及草酸氧化酶基因转入乳酸菌中，使其表达草酸降解酶，可达到持续有效降解草酸的效果。泌尿系结石和肠道微生物关系值得探讨。在前期前期工作的基础上，本课题通过宏基因组技术按全基因组测序和 16S rDNA 测序两种策略研究 10 种常见成分类型尿石症患者粪便中微生物群，并按成石危险因素分组分析肠道菌群差异和特点。我们成功的收集30例不同成分类型（10种常见结石成分）的初发尿石症和30例非泌尿系结石（对照组）患者粪、尿样本，术后结石样本确定成分类型决定是否入实验组，并在治疗前及时行24小时尿液成分分析，随后对粪便标本进行了测序，结果提示：与对照组比较，大量肠道微生物基因为泌尿系结石患者所特有，并且在不同结石成分中还存在差异，这些特有的微生物基因可能是泌尿系结石的致病或者保护基因；患者组或健康对照组肠道微生物在目科属水平上均有显著差异；teroides_coprocola_CAG_162，g_Paraprevotella，s_Clostridium_sp_ CAG_7可以作为特发性草酸钙结石的生物标记物种；egNOG分析提示患者组或健康对照组之间存在较多的直系同源簇，这些蛋白可能行使致病或者保护功能。总之，该课题揭示了患者和健康人群在微生物总体基因构成、物种组成和微生物功能组成上均有显著差异，探寻不同成分结石类型关联的特异性微生物群和功能基因，为肠道微生物群与尿石病因关系探索提供新思路