Studies on the increased incidence rate of colon cancer due to the excess intake of water soluble dietary fiber

为了明确是否有必要制定水溶性膳食纤维与不水溶性膳食纤维摄入比例的指导原则，我们研究了饲喂瓜尔胶或瓜尔胶加纤维素对大鼠结肠1,2-二甲基肼化学致癌作用的影响。所得结果如下：1。我们证实了先前报道的瓜尔胶对肿瘤形成的促进作用，具有统计学意义。我们发现，当2/3的瓜尔胶被纤维素取代时，增强的肿瘤形成被完全抑制。在这两种情况下都是1。和2。血清胆固醇和甘油三酯水平显著降低，每天总胆汁酸的粪便排泄量几乎增加了一倍。在1的情况下。粪便中总胆汁酸浓度与对照组（不饲喂膳食纤维）持平或显著高于对照组。在2的情况下。然而，粪便中总胆汁酸的浓度明显低于或几乎低于对照组的一半。在1的情况下。，去偶联活性较高，在2。，他们低于对照组。据此，在情形1中，DMH的排泄形式在消化道中解偶，甲氧基甲醇的葡萄糖醛酸缀合物更为完整。与病例相比，2只大鼠。7-α-去羟基化活性在情形1中较低。老鼠比对照组和案例2中的老鼠多。大鼠对事实表明，在盲肠中检测到的乳酸、醋酸或丙酸含量几乎翻了一番。与对照大鼠或病例2比较。老鼠。因此，病例1的粪便次级胆汁酸浓度。大鼠在其他各组中最低，病例1检出肿瘤。大鼠均为腺瘤。因此，膳食纤维均衡摄入指南的正式发布是值得期待的。

In order to make clear whether it is necessary to lay a guideline for the intake ratio of water souble dietary fiber to the water insoluble one, we investigated the effect of feeding guar gum or guar gum plus cellulose on the chemical carcinogenesis by 1,2-dimethylhydrazine of rat colon. The results obtained were as follows.1. We confirmed the precedent reports indicating the enhancement of tumor formation by feeding guar gum with statistical significance.2. We disclosed the fact that the enhanced tumor formation was suppressed completely when 2/3 of the guar gum was replaced with cellulose.3. In both cases of 1. and 2.,serum cholesterol and tryglyceride levels were decreased significantly, and fecal excretion per day of total bile acids were almost doubled.4. In the case of 1., the fecal concentration of total bile acids was in the same level to or significantly higher than the control (no dietary fiber fed). In the case of 2., however, the fecal concentration of total bile acids was significantly lower than or almost half of the control.5. In the case of 1., de-conjugation activities were higher, and in the case of 2., they were lower than the control group. Accordingly, the de-conjugation of the excretion form of DMH to the digestive tract, the glucuronate conjugate of methylazoxymethanol was deduced to be more complete in the case 1. when compared with the case 2 rats.6. 7-α-dehydroxylation activity was deduced to be lower in the case 1. rats than the control or case 2. rats on the fact that the amount of lactate, acetate or propionate detected in the cecum was almost double in the case 1. compared to the control rats or case 2. rats. Consequently, the concentration of fecal secondary bile acids of case 1. rats was the lowest among other groups and the neoplasma detected in case 1. rats were all adenoma. Thus, it is to be desired that the guideline for balanced intake of dietary fiber is officially published.