Metabolic epidemiology of colon cancer: effect of dietary fiber on fecal mutagens and bile acids in healthy subjects.
Metabolic epidemiology of colon cancer: effect of dietary fiber on fecal mutagens and bile acids in healthy subjects.
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发表时间：
1987-01
期刊：
影响因子：
11.2
通讯作者：
B. Reddy;C. Sharma;B. Simi;A. Engle;K. Laakso;P. Puska;R. Korpela
中科院分区：
文献类型：
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作者：
B. Reddy;C. Sharma;B. Simi;A. Engle;K. Laakso;P. Puska;R. Korpela
由于粪便诱变剂和次级胆汁酸在结肠癌发病机制中的潜在意义以及膳食纤维和结肠癌风险之间的负相关性，在15名健康男性和女性中研究了膳食小麦和黑麦纤维对粪便诱变活性和胆汁酸水平的影响，这些男性和女性食用高脂肪/中等低纤维饮食并排出高水平的粪便诱变剂和胆汁酸。每位参与者在食用正常饮食（对照）时提供了两份24小时粪便样本和3天饮食记录。然后要求所有受试者每天食用正常饮食加上11 g全麦面包形式的补充纤维，持续4周。在饮食干预的最后一周，每名受试者提供两份24小时粪便标本和一份3天的饮食记录。使用鼠伤寒沙门氏菌菌株TA 98和TA 100（存在和不存在微粒体活化）分析从两个阶段采集的粪便样本的胆汁酸和诱变剂。在所有受试者中，在纤维补充期间粪便次级胆汁酸的浓度显著降低。纤维补充剂也抑制了TA 100和TA 98的粪便致突变活性，有和没有微粒体活化。因此，全麦和黑麦面包形式的纤维摄入量增加可能会减少粪便诱变剂的产生和/或排泄，并降低人体粪便次级胆汁酸的浓度。
Because of potential significance of fecal mutagens and secondary bile acids in the pathogenesis of colonic cancer and of inverse association between dietary fiber and colonic cancer risk, the effect of dietary wheat and rye fiber on fecal mutagenic activity and bile acid levels was studied in 15 healthy men and women who were consuming high fat/moderately low fiber diets and excreting high levels of fecal mutagens and bile acids. Each participant provided two 24-h stool specimens and a 3-day diet record while consuming their normal diet (control). All subjects were then asked to consume their normal diet plus 11 g of supplemental fiber per day in the form of whole grain bread for 4 weeks. During the last week of diet intervention, each subject provided two 24-h stool specimens and a 3-day dietary record. Fecal samples collected from both periods were analyzed for bile acids and for mutagens using Salmonella typhimurium strains TA98 and TA100 with and without microsomal activation. The concentration of fecal secondary bile acids was significantly lower during the fiber supplemental period in all subjects. Fiber supplementation also inhibited the fecal mutagenic activity in TA100 and TA98 with and without microsomal activation. Thus, the increased fiber intake in the form of whole wheat and rye bread may reduce the production and/or excretion of fecal mutagens and decrease the concentration of fecal secondary bile acids in humans.