COCOA PAD II Trial: Microbiome Ancillary Study

摘要 可可黄烷醇来自可可树可可树的种子，具有治疗作用 可改善下肢血流灌注，逆转腓肠肌异常 肢体外周动脉疾病(PAD)患者的残疾。我们资助的可可垫II试验 (R01-AG068458)是一项多中心双盲随机试验，将测试可可黄烷醇的效果 PAD患者6个月随访期6分钟步行距离变化与安慰剂的比较。次要的 结果包括腓肠肌灌注、体力活动、肱动脉血流介导的扩张和 腓肠肌活检测量线粒体活性和骨骼肌健康。 初步证据支持我们的假设，即肠道微生物区系可能介导了 可可黄烷醇。首先，肠道微生物群代谢可可黄烷醇，产生代谢物进入 循环并到达这些代谢物可能发挥有益作用的靶器官。第二，可可 黄烷醇增加双歧杆菌和乳杆菌的丰度。但减少了梭状芽孢杆菌。在肠子里 微生物组。这些微生物群的变化与肌肉功能的改善和锻炼有关 能力以及减少氧化应激。因此，我们请求行政补编(PA 20-227) 为期12个月，以支持大便和血浆样本的收集和样本的准备 分析。收集的样本将被送往芝加哥大学埃里克·帕默博士的实验室进行分析。 在这一年的资助期间，我们预计将从大约50名参与者那里收集样本 基线和六个月随访期的大约40名参与者，他们是可可垫II的参与者 审判。我们将测试以下具体目标：第一，在PAD患者中，我们将评估可可 与安慰剂相比，黄烷醇有利于改变肠道细菌的多样性、组成和肠道微生物的相关性 6个月随访时的代谢组学。其次，在PAD患者中，随机服用可可黄烷醇，我们将 评估肠道细菌多样性、组成和肠道微生物是否发生了更有利的变化 基线和6个月随访之间的代谢物与6分钟内的更大改善相关 6个月随访时的步行和其他研究结果。第三，在患有PAD的人中，随机服用可可 黄烷醇，我们将评估肠道微生物组的基线特征是否与 对可可黄烷醇的反应程度，通过6分钟步行距离和 6个月随访的其他结果。如果我们的假设是正确的，这场审判将首次， 建立肠道微生物组作为可可黄烷醇对改善的影响的关键中介 人类的行走能力。研究结果还将描绘出可可黄醇的一个关键生物途径。 治疗，并将肠道微生物群确定为未来干预的重要治疗目标。

ABSTRACT Cocoa flavanols, from the seeds of theobroma cacao, the “cocoa” tree, have therapeutic properties that may improve lower extremity perfusion and reverse gastrocnemius muscle abnormalities that contribute to disability in people with lower extremity peripheral artery disease (PAD). Our funded COCOA PAD II Trial (R01-AG068458) is a multi-center double-blinded randomized trial that will test the effects of cocoa flavanols vs. placebo on change in six-minute walk distance at six month follow-up in people with PAD. Secondary outcomes include gastrocnemius perfusion, physical activity, brachial artery flow-mediated dilation and gastrocnemius muscle biopsy measures of mitochondrial activity and skeletal muscle health. Preliminary evidence supports our hypothesis that gut microbiota may mediate the beneficial effects of cocoa flavanols. First, gut microbiota metabolize cocoa flavanols to produce metabolites that enter the circulation and reach target organs where these metabolites may exert beneficial effects. Second, cocoa flavanols increase abundance of Bifidobacteria and Lactobacillus spp. but decrease Clostridium spp. in the gut microbiome. These microbiome changes have been associated with improved muscle function and exercise ability as well as reduced oxidative stress. Therefore, we request an Administrative Supplement (PA 20-227) for a 12 month period to support collection of stool and plasma samples and preparation of samples for analyses. Collected samples will be sent to Dr. Eric Pamer’s laboratory at the U. of Chicago for analyses. During this one year of funding, we anticipating collecting samples from approximately 50 participants at baseline and approximately 40 participants at six-month follow-up who are participants in the COCOA PAD II Trial. We will test the following specific aims: First, among people with PAD, we will assess whether cocoa flavanols, compared to placebo, favorably alter gut bacterial diversity, composition, and gut-microbe associated metabolomics at six-month follow-up. Second, among people with PAD randomized to cocoa flavanols, we will assess whether more favorable changes in gut bacterial diversity, composition, and gut microbe related metabolites between baseline and 6-month follow-up are associated with greater improvement in six-minute walk and other study outcomes at 6-month follow-up. Third, among people with PAD randomized to cocoa flavanols, we will assess whether baseline characteristics of the gut microbiome are associated with the degree of response to cocoa flavanols, measured by greater improvement in six-minute walk distance and other outcomes at 6-month follow-up. If our hypotheses are correct, this trial will, for the first time, establish the gut microbiome as a critical mediator of the effects of cocoa flavanols on improved walking performance in humans. Results will also delineate a key biologic pathway of cocoa flavanol therapy, and identify the gut microbiome as an important therapeutic target for future interventions.