MEASURING DIETARY FIBER

不同的膳食纤维（DF）来源引起不同的生理 应答 这项研究计划的长期目标是阐明 膳食纤维的作用机制。 吉伯对 胃肠道的生理和生物化学是一种 它的存在和新陈代谢的结果。 然而，净 发酵和未消化的DF的存在不能解释其效果 大便重量。 DF与结肠癌发生有关，尽管其 作用是有争议的，部分原因是流行病学和实验 数据不一致。 发酵产物的吸收，短 链脂肪酸（SCFA），已被证明，虽然没有DF是 目前被赋予了一个卡路里值。 这次比赛的总体目标是 更新是为了确定发酵的地点，速度和程度， 单胃种检验的假设，即率，网站和 发酵程度及其对微生物生长和代谢的影响 确定哪种DF来源会增加粪便重量，抑制毒性 或致癌代谢活动或提供净能量给宿主。 DF的发酵速率可以部分地通过其溶解度来预测， 虽然目前的分析方法低估了可溶性DF达到 结肠 有资料表明DF影响小肠分泌 粘蛋白。 其他数据表明，来自豆类的淀粉同化和 加工的粮食产品是不完整的。 的相对比例 到达结肠的可溶性DF、粘蛋白和淀粉将被确定为 他们会混淆DF发酵和粪便之间的关系 体重、微生物代谢和净能量生物利用度。 实验 将在完整和结肠切除大鼠以及猪中进行， 长期植入肠道的套管 植物-细菌-和 内源性CHO将根据以下方面进行区分： 溶解度、尺寸和中性及氨基糖组成。 相对速率 将确定SCFA生产的比例，以澄清拟议的 SCFA在粘膜细胞生长和抑制肝细胞增殖中的作用 胆固醇合成。 从拟议的研究结果将定义 预防和治疗便秘的最佳DF来源， 憩室病，并可能用于高胆固醇血症和结肠癌。 这些实验将提供证据表明，一些DF应分配 热量值，可能需要考虑作为能源， 糖尿病和减肥饮食和产品。

Different dietary fiber (DF) sources elicit different physiological responses. The long term goal of this research program is to elucidate the mechanisms of action for dietary fiber. Giber's effects on the physiology and biochemistry in the gastrointestinal tract are a consequence of both its presence and its metabolism. However, net fermentation and the presence of undigested DF do not explain its effect on stool weight. DF is implicated in colon carcinogenesis, although its role is controversial in part because epidemiological and experimental data have been inconsistent. Absorption of fermentation products, short chain fatty acids (SCFA), has been demonstrated, although no DF is currently assigned a caloric value. The overall aim of this competing renewal is to determine the site, rate and extent of fermentation in monogastric species to test the hypotheses that is the rate, site and extent of fermentation and its effect on microbial growth and metabolism that determine which DF sources will increase stool weight, inhibit toxic or carcinogenic metabolic activity or provide net energy to the host. DF's rate of fermentation can be predicted in part by its solubility, although current analytic methods underestimate soluble DF reaching the colon. Some data indicate that DF affects secretion of small bowel mucin. Other data indicate that starch assimilation from legumes and processed grain products is incomplete. The relative proportion of soluble DF, mucin and starch reaching the colon will be determined as they would confound the relationships between DF fermentation and stool weight, microbial metabolism and net energy bioavailability. Experiments will be conducted in intact and colectomized rats, and in swine with cannulas chronically implanted in the gut. Plant-, bacterially- and endogenously-derived CHO will be distinguished on the basis of solubility, size and neutral and amino sugar composition. Relative rates and ratios of SCFA production will be determined to clarify proposed roles of SCFA in mucosal cell growth and in inhibiting hepatic cholesterol synthesis. Results from the proposed research will define optimal DF sources for the prevention and treatment of constipation and diverticulosis, and possibly for hypercholesterolemia and colon cancer. These experiments will provide evidence that some DF should be assigned caloric values and may need to be considered as energy sources in diabetic and weight reduction diets and products.