Raymond T L, Connor W E, Lin D S, Warner S, Fry M M, Connor S L
J Clin Invest. 1977 Dec;60(6):1429-37. doi: 10.1172/JCI108904.
To identify any metabolic effects of dietary fiber upon cholesterol metabolism in man, six adult volunteer subjects were fed eucaloric cholesterol-free formula diets, with and without added dietary fiber for two 4-wk periods. A large quantity of dietary fiber was fed, some 60 g of plant cell wall material (or 16 g of crude fiber) derived from corn, beans, bran, pectin, and purified cellulose. This provided about five times the fiber intake of the typical American diet. The addition of fiber to the cholesterol-free diet did not change either the plasma cholesterol level (171+/-21 mg/dl, SEM, to 167+/-18) or the triglyceride (103+/-39 to 93+/-27 mg/dl). The excretion of both endogenous neutral steroids and bile acids were unchanged with fiber (505+/-41 to 636+/-75 mg/day and 194+/-23 to 266+/-47 mg/day, respectively.) However, total fecal steroid excretion was increased 699+/-29 to 902+/-64 mg/day, P < 0.025). With fiber, intestinal transit time was decreased (59+/-9 to 35+/-8 h, P < 0.005), and both the wet and dry stool weights were greatly increased.A second group of six subjects was fed similar diets containing 1,000 mg cholesterol derived from egg yolk. The addition of fiber to the 1,000-mg cholesterol diet did not alter either plasma cholesterol level (233+/-26 to 223+/-36 mg/dl) or triglyceride (102+/-19 to 83+/-11 mg/dl). The excretion of endogenous neutral steroids (618+/-84 to 571+/-59 mg/day), of bile acids (423+/-122 to 401+/-89 mg/day), and of total fecal steroids (1,041+/-175 to 972+/-111 mg/day) were unchanged by fiber. The absorption of dietary cholesterol was not altered when fiber was added to the 1,000-mg cholesterol diet (44.0+/-3.3 to 42.9+/-2.5%). A two-way analysis of variance utilizing both groups of subjects indicated a significant (P < 0.001) effect of dietary cholesterol upon the plasma cholesterol concentration. We concluded that a large quantity of dietary fiber from diverse sources had little or no effect upon the plasma lipids and sterol balance in man in spite of the fact that intestinal transit time and stool bulk changed greatly.
为确定膳食纤维对人体胆固醇代谢的任何代谢影响，六名成年志愿者受试者接受了等热量无胆固醇配方饮食，在两个为期4周的阶段中，一组饮食添加膳食纤维，另一组不添加。给予了大量膳食纤维，约60克源自玉米、豆类、麸皮、果胶和纯化纤维素的植物细胞壁物质（或16克粗纤维）。这提供了约为典型美国饮食纤维摄入量五倍的量。在无胆固醇饮食中添加纤维，既未改变血浆胆固醇水平（从171±21毫克/分升，标准误，变为167±18），也未改变甘油三酯水平（从103±39变为93±27毫克/分升）。内源性中性类固醇和胆汁酸的排泄量在添加纤维后均未改变（分别为从505±41毫克/天变为636±75毫克/天和从194±23毫克/天变为266±47毫克/天）。然而，粪便中总类固醇排泄量增加，从699±29毫克/天增至902±64毫克/天，P<0.025）。添加纤维后，肠道转运时间缩短（从59±9小时变为35±8小时，P<0.005），且湿粪便和干粪便重量均大幅增加。第二组六名受试者接受了含有1000毫克源自蛋黄胆固醇的类似饮食。在含1000毫克胆固醇的饮食中添加纤维，既未改变血浆胆固醇水平（从233±26毫克/分升变为223±36毫克/分升），也未改变甘油三酯水平（从102±19毫克/分升变为83±11毫克/分升）。纤维对内源性中性类固醇（从618±84毫克/天变为571±59毫克/天）、胆汁酸（从423±122毫克/天变为401±89毫克/天）和粪便中总类固醇（从1041±175毫克/天变为972±111毫克/天）的排泄量均无影响。在含1000毫克胆固醇的饮食中添加纤维时，膳食胆固醇的吸收未改变（从44.0±3.3%变为42.9±2.5%）。对两组受试者进行的双向方差分析表明，膳食胆固醇对血浆胆固醇浓度有显著影响（P<0.001）。我们得出结论，尽管肠道转运时间和粪便量发生了很大变化，但来自不同来源的大量膳食纤维对人体血浆脂质和固醇平衡几乎没有影响。
