Diet and the colonic exfoliome: a novel, non-invasive approach to testing interventions in humans

饮食和结肠脱落组：一种测试人类干预措施的新型非侵入性方法

• 批准号: 10603601
• 负责人: Robert Stephen Chapkin
• 金额: $ 19.05万
• 依托单位: FRED HUTCHINSON CANCER CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10603601
• 关键词: Diet; colonic; exfoliome; novel; non

PROJECT SUMMARY Diet is an important risk factor for colorectal cancer (CRC) and several dietary constituents implicated in CRC are modified by gut microbial metabolism. Microbial fermentation of dietary fiber produces short chain fatty acids, e.g., acetate, propionate, and butyrate. Dietary fiber has been shown to reduce colon tumors in animal models and, in vitro, butyrate influences cellular pathways important to cancer risk. Further, work from our group suggests that the combined effects of butyrate and omega-3 polyunsaturated fatty acids (n-3 PUFA) may enhance the chemopreventive potential of these dietary constituents. We postulate that the relatively low intakes of n-3 PUFA and fiber in Western populations and the failure to address interactions between these dietary components may explain why chemoprotective effects of n-3 PUFA and fermentable fibers have not been detected consistently in prospective cohort studies. We hypothesize that the combined effects of long- chain n-3 PUFA supplementation and supplemental highly fermentable fiber will alter critical pathways important to CRC prevention, particularly intrinsic mitochondrial-mediated programmed cell death resulting from the accumulation of lipid reactive oxygen species (ferroptosis), cell proliferation, and the eicosanoid/inflammation pathways. We propose a randomized, controlled crossover pilot study in 30 healthy men and women (50-75 y) to compare supplemental soluble fiber (35 g/d) + supplemental n-3 PUFA (6 g/d EPA+DHA), in quantities mirroring mean daily intakes associated with lower CRC risk, with a maltodextrin and corn oil control. Stool samples will be collected at the beginning, middle (day 15), and end of each of the two 30-day intervention periods. Using a novel, cost-effective, non-invasive approach, we will evaluate differences in global gene expression signatures in the stool exfoliome (i.e., sloughed colonic epithelial cells in stool) using RNA-Seq. We will focus on pathways related to colonic cell proliferation and apoptosis/ferroptosis, cell phenotype, and inflammatory response. Further, we will evaluate changes in gut microbial functional genes involved in butyrate production using droplet digital PCR (ddPCR). The collection of multiple samples over the intervention periods will provide a critical measure of longitudinal changes in response to the supplemental n-3 PUFA and fermentable fiber. This proposed pilot human mechanistic study will be the first in humans to integrate and characterize the relationships between n-3 PUFA and fermentable fiber exposure that modulate programmed cell death and other CRC-related cell-signaling pathways through metabolic activities of the gut microbiome. Results of this controlled intervention will help to translate the current mechanistic knowledge from preclinical animal models to humans and to de-risk and inform approaches for CRC prevention. Interrogating the stool exfoliome is a novel, cost-effective, non-invasive approach to studying effects of interventions on the human gut.

项目摘要 饮食是结直肠癌（CRC）的一个重要危险因素， CRC通过肠道微生物代谢进行修饰。微生物发酵膳食纤维产生短链 脂肪酸，例如，乙酸、丙酸和丁酸。膳食纤维已被证明可以减少结肠肿瘤， 在动物模型和体外试验中，丁酸盐影响对癌症风险很重要的细胞途径。此外，工作从 我们的研究小组认为，丁酸和ω-3多不饱和脂肪酸（n-3 PUFA）的联合作用 可以增强这些饮食成分的化学预防潜力。我们假设相对较低的 西方人群中n-3 PUFA和纤维的摄入量以及未能解决这些之间的相互作用 膳食成分可以解释为什么n-3 PUFA和可发酵纤维的化学保护作用 在前瞻性队列研究中一致检测到。我们假设长期的- 链n-3多不饱和脂肪酸的补充和补充高发酵纤维将改变关键途径 对CRC预防很重要，特别是内源性肿瘤介导的程序性细胞死亡， 从脂质活性氧的积累（铁凋亡），细胞增殖， 类花生酸/炎症途径。 我们建议在30名健康男性和女性（50-75岁）中进行一项随机、对照交叉初步研究， 比较补充可溶性纤维（35 g/d）+补充n-3 PUFA（6 g/d EPA+DHA）的量 反映了与较低CRC风险相关的平均每日摄入量，以麦芽糊精和玉米油为对照。凳子 将在两次30天干预的开始、中间（第15天）和结束时采集样本 时期使用一种新的，具有成本效益的，非侵入性的方法，我们将评估全球基因的差异， 粪便脱落组中的表达标记（即，粪便中脱落的结肠上皮细胞）。 我们将重点关注与结肠细胞增殖和凋亡/铁凋亡，细胞表型， 炎症反应。此外，我们将评估丁酸盐相关的肠道微生物功能基因的变化 使用液滴数字PCR（ddPCR）进行生产。在干预期间收集多个样本 将提供响应于补充n-3 PUFA的纵向变化的关键测量， 可发酵纤维 这项拟议的试点人类机制研究将是第一个在人类中整合和表征 n-3多不饱和脂肪酸和可发酵纤维暴露之间的关系，调节程序性细胞死亡， 通过肠道微生物组的代谢活动的其他CRC相关细胞信号传导途径。成果 控制性干预将有助于从临床前动物模型中转化当前的机制知识， 并降低风险和告知CRC预防方法。询问粪便脱落物是一种 新的，具有成本效益的，非侵入性的方法来研究干预对人类肠道的影响。