肠道微生物拓扑结构与华法林药效个体化差异的相关性研究

Individual variability among patients plays an important role in determining the dose of warfarin that should be used when oral anticoagulation is initiated. However practical methods of using genetic information have not been showed to have a stronger effect on Chinese people. It is reported that human gut microbiota play a fundamental role in absorption mechanism of vitamin K, while warfarin is a competitive inhibitor with vitamin K. The purpose of this study was to determine whether gut microbiota contribute to the variability in the maintenance dose of warfarin. Considering prediction of the maintenance dose of warfarin needs multiple markers, we have developed an algorithm for estimating the appropriate warfarin dose that was base on genetic data and microbial diversity analysis methods. Firstly, we screen the microbial markers and their topology associated with the variation in warfarin dose by single-molecule DNA sequencing technologies. Then a new algorithm for estimating the appropriate warfarin dose, integrating topology of gut microbiota, clinical and genetic data, was built based on bioinformatics. Lastly, animal models were used to identify the function of the gut microbial markers. The new algorithm needs to be evaluated in validation sets to illustrate the correlation between topology of gut microbiota and the variation in warfarin sensitivity.

华法林药效存在较大个体差异及种族差异，临床上基于药物基因组学指导华法林用药剂量，但对中国人群预测效果不佳。研究表明肠道微生物直接参与维生素K（VitK）循环，而华法林竞争性抑制VitK环氧化物还原酶，阻断VitK循环发挥抗凝效用。为此，本课题提出将肠道微生物拓扑结构作为预测华法林药效个体差异标志物的假说。由于准确预测华法林给药剂量需整合多元标志物，本课题在已建立的基于基因组剂量预测模型及微生物多样性分析平台的基础上，首先通过单分子测序技术对肠道微生物进行鉴别、定量，筛选华法林药效相关微生物标志物及其拓扑结构；再以此为基础，采用生物信息学方法，构建整合肠道微生物拓扑结构、药物基因组学、个体临床指标等多元标志物的华法林剂量预测新模型；最后通过构建体外动物模型及剂量预测训练集验证微生物标志物活性及新模型预测度，阐明肠道微生物拓扑结构和华法林药效个体差异相关性，为临床华法林个体化治疗提供新思路。

华法林药效存在较大个体差异，基于药物基因组学指导华法林用药的剂量对中国人群预测效果不佳。华法林竞争性抑制VitK环氧化物还原酶，阻断VitK循环发挥抗凝效用，而研究表明，肠道微生物可直接参与维生素K（VitK）循环。为此，本课题提出将肠道微生物拓扑结构作为预测华法林药效个体差异标志物的假说。本课题建立了血浆、粪便样本中多种VitK同时定量检测方法，并对临床样本进行了检测，结果表明粪便中VK1浓度是其他两种VitK型的10-50倍，而血浆中不同VitK数量级一致。同时采用高通量测序技术对肠道微生物拓扑结构进行了分析，PCA、NMDS等结果均表明华法林敏感性不同的患者，其肠道微生物拓扑结构具有显著差异，并筛选出了和临床信息及VitK浓度相关的影响药效的潜在微生物标志物，药效预测模型准确度分析结果显示敏感性诊断微生物模型具有一定的准确性，可为华法林个体化精准用药治疗提供参考。