LEGUME FEEDING STUDY

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 高豆类、低血糖指数饮食的有益效果的工作假设是，食物中的膳食纤维含量可能会降低碳水化合物的吸收速度，降低餐后血糖和胰岛素反应，从而降低C-肽和其他胰岛素抵抗标记物的水平。豆类中高水平的可发酵纤维将被结肠细菌降解为短链脂肪酸，包括丁酸，一种具有抗炎和抗肿瘤特性的分子。胰岛素的降低和丁酸的升高都会降低CRP和其他炎症生物标志物，并改变粪便结肠细胞中炎症和胰岛素相关基因的表达水平。另一个正在研究的假设是，高豆类、高纤维饮食会导致循环中的CCK、Ghrelin和Leptin水平的变化，这将增加饱腹感和减轻体重。 研究目标 这是一项随机交叉控制喂养研究，每个参与者将食用四周的高豆类、低血糖指数饮食，以及四周的对照美国饮食，两次饮食之间有三周的休息时间。这两个节食期的体重将保持稳定。额外的节食期将是可选的，在此期间，他们将食用相同的富含豆类的饮食，但将允许减肥。这项研究将有四组男性参与者：1.以前有腺瘤和IR病史；2.以前有腺瘤病史但没有IR；3.没有腺瘤病史；以及4.没有IR病史，没有腺瘤病史。主要目标是评估饮食对该人群中两个终点--C-反应蛋白和C-肽的总体影响。第二个目标是评估这些干预相关终点的变化是否会因IR状态或腺瘤病史而不同。此外，还将测量粪便钙保护素和结肠细胞RNA，以评估胃肠道炎症的变化。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The working hypothesis for the beneficial effects of a high legume, low glycemic index diet is that the dietary fiber content of the food may reduce the rate of the absorption of the carbohydrates and lower the postprandial glycemic and insulinemic responses leading to a reduced level of C-peptide and other markers of insulin resistance. The high level of fermentable fibers in legumes will be degraded by colonic bacteria to short chain fatty acids, including butyrate, a molecule with demonstrated anti-inflammatory and anti-neoplastic properties. The lowering of insulin and the increase in butyrate will both lower CRP, and other biomarkers of inflammation, and will alter expression level of inflammatory and insulin related genes in fecal colonocytes. An additional hypothesis being investigated is that a high legume, high fiber diet will result in changes in circulating levels of cholecystokin (CCK), ghrelin, and leptin which will increase satiety and reduce body weight. Study Objectives This is a randomized crossover controlled feeding study in which each participant will consume a high legume, low glycemic index diet for four weeks and a control American diet for four weeks, with a three week break between diets. These two diet periods will be weight stable. An additional diet period will be optional in which they will consume the same legume rich diet, but weight loss will be permitted. The study will have four groups of male participants: 1. previous history of adenomas and IR; 2. previous history of adenomas and not IR; 3. IR with no history of adenomas; and 4. non-IR and no history of adenomas. The primary objective is to assess an overall effect of diet on the two endpoints, C-reactive protein and C-peptide in this population. A secondary objective is to assess whether changes in these intervention-related endpoints will differ by IR status or a history of adenomas. In addition, fecal calprotectin and colonocyte RNA will be measured to assess changes in gastrointestinal inflammation.