COCOA PAD II: Effect of Cocoa Flavanols on the Gut Microbiome and Functional Performance

摘要 下肢外周动脉疾病(PAD)影响着全球超过2.3亿人，是一种主要的 致残原因。然而，目前对PAD的治疗方法寥寥无几。可可黄烷醇，来自Theobroma的种子 可可是一种“可可树”，具有治疗作用，可以改善小腿肌肉的血液灌注量，逆转 导致PAD残疾的腓肠肌异常。我们最近投资的可可垫II 试验(R01-AG068458)是一项多中心双盲随机试验，将测试可可的效果 黄烷醇与安慰剂对PAD患者6个月随访6分钟步行距离变化的比较。 次要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 有证据支持我们的假设，即肠道微生物区系可能是可可有益效果的关键媒介 黄烷醇。首先，肠道微生物群代谢可可黄烷醇，包括表儿茶素(主要的可可黄烷醇) 产生进入循环并到达目标器官的代谢物。这些代谢物有许多益处。 效果。微生物来源的黄醇代谢产物增加内皮型一氧化氮合酶的磷酸化和 一氧化氮的产生。第二，补充可可黄烷醇可能会促进肠道微生物类群。 与健康有关。因此，我们现在提议对可可垫II试验进行一项辅助研究，这将 使我们能够收集和分析在基线和六个月随访期间收集的粪便和血浆样本 100名患有PAD的参与者，他们将参加可可PAD II试验。我们将测试以下特定的 目的：首先，在PAD患者中，我们将确定基线肠道微生物多样性和 成分与可可黄烷醇的反应程度有关，通过更大的改善来衡量 在6个月时进行6分钟步行距离和腓肠肌灌流。第二，我们将确定 与安慰剂相比，可可黄烷醇是否有利于改变肠道微生物的多样性和组成- 一个月的随访。第三，我们将确定可可黄醇是否会引起肠道微生物的变化 与安慰剂相比，基线和6个月随访之间的成分与更多 改善6分钟步行距离和腓肠肌血流灌注。最后，我们将进行微生物- 6个月随访时血液样本的相关代谢组谱分析，以确定 与6个月后改善的6分钟步行距离和腓肠肌的肌肉灌注有关。 向上。如果我们的假设是正确的，这项试验将首次建立肠道微生物组作为一种 PAD患者改善步行能力的关键调节因子。结果还将描绘出一个 改善PAD步行能力的关键生物途径，从而确定肠道微生物群 PAD未来干预的治疗靶点。

ABSTRACT Lower extremity peripheral artery disease (PAD) affects more than 230 million people worldwide and is a major cause of disability. Yet few medical therapies exist for PAD. Cocoa flavanols, from the seeds of theobroma cacao, the “cocoa” tree, have therapeutic properties that may improve calf muscle perfusion and reverse the gastrocnemius muscle abnormalities that contribute to disability in PAD. Our recently 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 be key mediators of the beneficial effects of cocoa flavanols. First, gut microbiota metabolize cocoa flavanols including epicatechin (the main cocoa flavanol) to produce metabolites that enter the circulation and reach target organs. The metabolites exert many beneficial effects. Microbe-derived flavanol metabolites increase phosphorylation of endothelial nitric oxide synthase and nitric oxide production. Second, dietary supplementation of cocoa flavanols may promote gut microbial taxa associated with health. Therefore, we now propose an ancillary study to the COCOA PAD II Trial that will enable us to collect and analyze stool and plasma samples collected at baseline and six month follow-up from 100 participants with PAD who will be enrolled in the COCOA PAD II Trial. We will test the following specific aims: First, among people with PAD, we will determine whether baseline gut microbial diversity and composition are associated with the degree of response to cocoa flavanols, measured by greater improvement in six-minute walk distance and gastrocnemius perfusion at 6-month follow-up. Second, we will determine whether cocoa flavanols, compared to placebo, favorably alter gut microbial diversity and composition at six- month follow-up. Third, we will determine whether cocoa flavanol-induced changes in gut microbial composition, compared to placebo, between baseline and 6-month follow-up are associated with greater improvement in six-minute walk distance and gastrocnemius perfusion. Finally, we will perform microbe- associated metabolomic profiling of blood samples at six-month follow-up to identify metabolomic profiles that are associated with improved six-minute walk distance and gastrocnemius muscle perfusion 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 improved walking performance in people with PAD. Results will also delineate a key biologic pathway of improved walking performance in PAD, thereby identifying the gut microbiome a therapeutic target for future interventions in PAD.