基于多组学分析对新疆地区维吾尔族、汉族溃疡性结肠炎肠道菌群及代谢差异的研究

This study is based on the past, we have been found in Xinjiang Uygur and Han ulcerative colitis in patients with clinical phenotype differences：Uygur patients with a single age peak of onset and the age of onset is small, the disease is serious, the disease is widespread, the complication is high, the effect is poor, the recurrence rate is high, And HLA-DRB1, FUT2 and IL-23R gene polymorphisms were different in the incidence of ulcerative colitis between the two ethnic groups.First,This distinguish used macrogeome and metabolomics to study the differences between the intestinal flora and fecal metabolites between Xinjiang Uygur ethnic group and Han groups, and further analyzed the correspondence between them. To understand the possible metabolic pathways associated with this difference. After wards,the gut microbiota of UC model rats and normal rats should be manipulated via fecal microbiota transplantation with representative samples, and then to detect the expression of cytokines in colonic mucosa. In order to observe the effect of different bacteria on intestinal mucosal inflammation in rats.The medium conditions is Controlled by significant differences in metabolites,we should cultivate the mucosal epithelial cells of UC model rats and normal rat intestinal , and the expression of cytokines in colonic mucosa will also be detected to observe the effect of different metabolites on the inflammatory response of intestinal epithelial cells in rats.In order to verify the effects of different intestinal flora and fecal metabolites on the occurrence of UC in patients with UC, and to elucidate the significance of intestinal flora in the occurrence and development of UC in Uygur and Han nationalities in Xinjiang.

我们前期研究发现新疆地区维吾尔、汉UC患者临床表型存在差异：维吾尔族患者为单一发病年龄高峰、发病年龄小、病情重、病变广泛、并发症发生率高、疗效差、复发率高，且HLA-DRB1、FUT2和IL-23R基因多态性与UC发病存在民族差异性。本研究首先利用宏基因组和代谢组学技术，寻找肠道菌群和粪便代谢物在维、汉UC患者中的差异，分析差异相关的代谢通路，阐明肠道菌群与维、汉UC发生及临床表型的关系。随后用具代表性的差异样本制备粪菌液，对UC大鼠及正常大鼠进行粪菌移植，取结肠粘膜组织，检测UC相关细胞因子的表达，观察差异菌对大鼠肠粘膜炎症反应的影响；并以差异代谢产物控制培养条件，培养UC大鼠及正常大鼠肠粘膜上皮细胞，检测UC相关细胞因子表达，观察差异代谢物对大鼠肠粘膜上皮细胞炎症反应的影响，进而验证维、汉UC患者不同肠道菌群和粪便代谢物对UC发生的影响，阐明肠道菌群在新疆维、汉UC发生、发展中的意义。

本课题组前期研究发现新疆地区维吾尔、汉UC患者临床表型存在差异：维吾尔族患者为单一发病年龄高峰、发病年龄小、病情重、病变广泛、并发症发生率高、疗效差、复发率高，且基因多态性与UC发病存在民族差异性。因此本研究首先初步通过对新疆地区维吾尔族及汉族UC患者与其1：1匹配健康亲属对照组粪便样本进行16S rRNA基因V3-V4区扩增高通量测序，筛选出两民族UC患者差异表达微生物及具有疾病鉴别能力的菌属；通过液相色谱-质谱联用（LC-MS）代谢组学平台筛选出了两民族粪便代谢物中的潜在生物标志物。综合微生物多样性和代谢组实验结果，通过两组学关联整合分析，验证两民族UC患者关键差异表达的微生物与代谢物之间的相关性；最后通过UC大鼠模型分别进行两民族患者粪菌液的粪菌移植，进一步验证肠道微生物及代谢差异与UC肠黏膜细胞炎症的相关性。结果显示维吾尔族与汉族UC患者肠道微生物在结构、多样性上均存在差异。克里斯滕森氏菌属等6种微生物种属对维吾尔族UC患者与健康对照组有一定鉴别诊断能力。维吾尔族UC患者与汉族UC患者间分别相较于其匹配健康亲属肠道粪便代谢物的变化存在差异。汉族UC患者与正常对照组间筛选出2种潜在生物标志物，维吾尔族UC组与正常对照组间筛选出21种潜在生物标志物。Omega-3花生四烯酸作为潜在生物标志物在维吾尔族UC患者中显著降低。两组学关联整合分析发现，维吾尔族UC患者中嗜血杆菌属与N-乙酰半乳糖胺的高度负相关，嗜血杆菌属很可能通过影响N-乙酰半乳糖胺表达量影响肠粘膜屏障，而汉族UC患者中未观察到此关联特征。维吾尔族及汉族UC患者肠道微生物及代谢水平的差异可能通过影响IL-6的表达水平造成疾病表现的差异。肠道微生物结构的差异与代谢水平间的相互作用及Omega-3与IL-6间的作用可能与新疆地区维吾尔族UC患者特殊临床表现及遗传背景相关。维吾尔族及汉族UC患者粪菌液灌肠在正常大鼠中没有引起炎症因子表达的差异，肠道微生物及其所影响的代谢水平可能是UC疾病的促进因素而不是始动因素。