Denbesten L, Connor W E, Kent T H, Lin D
J Lipid Res. 1970 Jul;11(4):341-5.
In one normal subject, J.S., fed several formula diets in a sterol balance study, only 25-58% of the ingested plant sterols were recovered from the stool. The dietary plant sterols were completely recovered from the stools of five other men. Plant sterol recovery was complete in all men when a diet of mixed general foods was consumed. Since the chief differences in composition of the formula and the diet of mixed general foods were related to the different contents of cellulose and lactose, these components were added to the formula diet of J.S., and plant sterol balance studies were then carried out. The addition of fresh celery or pulverized cellulose to the formula diet partially corrected the usual fecal loss of plant sterols (80% being recovered). Lactose in the formula was only slightly corrective. However, the addition of both cellulose and lactose led to complete recovery of the ingested plant sterols in the feces. Bacterial cultures of stools were incubated with added cholesterol-4-(14)C, and a linear relationship between losses of sterol during balance studies and in vitro incubations was observed; that is, a considerable loss of the labeled cholesterol from cultures after the formula diet, but not after the diet of mixed general foods. This in vitro loss was also corrected by the addition of cellulose and lactose to the formula diet. The loss of the sterol nucleus in the intestinal tract may occur at times because of the lack of certain dietary constituents. It is hypothesized that the metabolism of intestinal tract bacteria is altered when certain constituents are not present in the diet, and that these bacteria may then degrade the sterol nucleus.
在一项固醇平衡研究中，给一名正常受试者J.S.喂食了几种配方饮食，从粪便中仅回收了摄入的植物固醇的25%-58%。而在其他五名男性的粪便中，膳食植物固醇被完全回收。当食用混合普通食物的饮食时，所有男性的植物固醇回收均为完全回收。由于配方饮食和混合普通食物饮食在成分上的主要差异与纤维素和乳糖的不同含量有关，因此将这些成分添加到J.S.的配方饮食中，然后进行植物固醇平衡研究。在配方饮食中添加新鲜芹菜或粉碎的纤维素部分纠正了通常粪便中植物固醇的损失（回收了80%）。配方中的乳糖仅有轻微的纠正作用。然而，同时添加纤维素和乳糖可使粪便中摄入的植物固醇完全回收。将粪便的细菌培养物与添加的胆固醇-4-(14)C一起孵育，观察到平衡研究期间和体外孵育期间固醇损失之间存在线性关系；也就是说，喂食配方饮食后培养物中标记胆固醇有相当大的损失，但喂食混合普通食物饮食后则没有。通过在配方饮食中添加纤维素和乳糖也纠正了这种体外损失。由于缺乏某些膳食成分，肠道中固醇核的损失有时可能会发生。据推测，当饮食中不存在某些成分时，肠道细菌的代谢会发生改变，然后这些细菌可能会降解固醇核。
