BREATH MARKERS OF COLONIC FERMENTATION

结肠发酵的呼吸标志物

• 批准号: 3423311
• 负责人: LOIC LE MARCHAND
• 金额: $ 3.62万
• 依托单位: UNIVERSITY OF HAWAII AT MANOA
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-09-30 至 1992-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3423311
• 关键词: Hawaii; Hawaiian; biomarker; breath composition; breath tests; cancer risk; colon; colon neoplasms; ethnic group; fermentation; gas chromatography; gender difference; human subject; hydrogen; methane; racial /ethnic difference

Although there is substantial evidence that dietary fat is positively and dietary fiber negatively associated with colon cancer, some "anomalies" in the epidemiology of this disease have been observed. For example, in Hawaii, Japanese have high rates of colon cancer despite a relatively low fat intake, and Hawaiians experience a low risk despite a high fat intake. Both groups have a similarly low fiber intake. It is hypothesized that these anomalies, as well as other inconsistencies in the epidemiologic literature, may be explained by a protective effect of increased colonic fermentation against colon cancer. The present application will test this hypothesis in a correlation study, and pretest two biochemical markers of fermentation (breath hydrogen and breath methane) for use in epidemiologic studies. Subjects for this project will be randomly selected among population controls newly interviewed for two ongoing case-control studies conducted by our group. End alveolar breath samples will be obtained by having the subjects exhale an end expiratory sample into a 20-ml syringe, 3-hours after dinner on the day of the interview and again within 15 minutes of rising the following morning. These two measurements appear sufficient to correctly rank individuals according to their daily breath hydrogen excretion. Participants will mail in the breath samples for hydrogen and methane analysis by gas-chromatography. Breath hydrogen is known to have a high validity, sensitivity and specificity as a marker of fermentation. It also has a high within-person variability which makes it appropriate for studies at the population level only. Although breath methane appears to be less specific for fermentation, it has been correlated with colon cancer risk among certain populations. The present study will investigate among 350 men and women the correlation between the population means for these markers and colon cancer incidence rates among ten ethnic and sex groups living in Hawaii, as a first step in testing the fermentation hypothesis. If the results are supportive of an association, we plan to seek separate funding to investigate whether these markers can be used in studies at the individual level, by using repeated measurements.

虽然有大量证据表明，膳食脂肪是积极的， 膳食纤维与结肠癌负相关，一些“异常”， 对该病的流行病学进行了观察。例如在 夏威夷，日本人结肠癌的发病率很高，尽管相对较低， 夏威夷人的风险很低，尽管他们的脂肪摄入量很高。 两组人的纤维摄入量都很低。它是假设 这些异常，以及其他不一致的流行病学 文献，可以解释为增加结肠的保护作用， 发酵对结肠癌。本申请将对此进行测试。 相关性研究中的假设，并预先测试两个生化标志物， 流行病学用发酵（呼出氢和呼出甲烷） 问题研究 本项目的受试者将在人群中随机选择 两项正在进行的病例对照研究的新访谈对照 我们的团队。将通过以下方式获得肺泡呼气末样本： 受试者将呼气末样品呼出到20 ml注射器中，3小时 面试当天晚餐后和面试后15分钟内 第二天早上起床。这两项测量似乎足以 根据每天呼吸的氢，正确地对个人进行排名 排泄参与者将邮寄呼吸样本的氢和 用气相色谱法分析甲烷。众所周知，呼吸氢具有 作为发酵标志物有效性、灵敏度和特异性高。它 也有很高的人内变异性，这使得它适合于 仅在人口水平上进行研究。尽管呼出的甲烷 发酵特异性较低，与结肠癌有关 某些人群的风险。 本研究将在350名男性和女性中调查 这些标志物的人群平均值与结肠癌发病率之间 生活在夏威夷的10个种族和性别群体之间的比率，作为第一步， 验证发酵假说 如果结果支持关联，我们计划寻求单独的 研究这些标记物是否可以用于研究 个人水平，通过重复测量。