Favier M L, Moundras C, Demigné C, Rémésy C
Laboratoire des Maladies Métaboliques, I.N.R.A. de Clermont-Ferrand/Theix, Ceyrat, France.
Biochim Biophys Acta. 1995 Sep 14;1258(2):115-21. doi: 10.1016/0005-2760(95)00107-n.
The purpose of this work was to assess the respective role of bile acid excretion and of the end-products of cecal fermentations in the cholesterol-lowering effect of complex carbohydrates. The effects of two different fermentable carbohydrates (guar gum, beta-cyclodextrin), and sequestrant resin (cholestyramine) have been investigated in male Wistar rats. Guar gum and beta-cyclodextrin are broken down in the large bowel, with fermentation rich in propionic acid (37% against 26% for control), whereas cholestyramine did not enhance cecal fermentation. beta-Cyclodextrin and guar gum were less potent than cholestyramine to enhance bile acids and sterol excretion. Nevertheless, fermentable carbohydrates exerted a more potent cholesterol-lowering effect than cholestyramine. beta-Cyclodextrin also depressed triacylglycerol-rich lipoprotein (TGRLP). Fermentable carbohydrates lowered cholesterol of LDL and HDL1 fractions. The induction of hepatic HMG-CoA reductase was practically proportional to rate of fecal steroid excretion. Moreover, with beta-cyclodextrin, hepatic HMG-CoA reductase induction was concomitant to a decrease in fatty acid synthase (FAS) activity. Thus, the cholesterol-lowering effect of fermentable carbohydrates could be related to a depressed lipogenesis, as well as to an accelerated removal of HDL1, in relation to an elevated hepatic demand of cholesterol. In conclusion, fermentable carbohydrates could favour cholesterol elimination and have a general lipid-lowering effect by exerting more complex physiological effects than cholestyramine.
本研究旨在评估胆汁酸排泄和盲肠发酵终产物在复合碳水化合物降胆固醇作用中的各自作用。在雄性Wistar大鼠中研究了两种不同的可发酵碳水化合物（瓜尔胶、β-环糊精）和螯合剂树脂（考来烯胺）的作用。瓜尔胶和β-环糊精在大肠中分解，发酵产生富含丙酸的物质（37%，而对照组为26%），而考来烯胺不会增强盲肠发酵。β-环糊精和瓜尔胶在促进胆汁酸和甾醇排泄方面的效力低于考来烯胺。然而，可发酵碳水化合物的降胆固醇作用比考来烯胺更强。β-环糊精还能降低富含三酰甘油的脂蛋白（TGRLP）。可发酵碳水化合物可降低低密度脂蛋白（LDL）和高密度脂蛋白1（HDL1）组分中的胆固醇。肝脏HMG-CoA还原酶的诱导实际上与粪便类固醇排泄率成正比。此外，对于β-环糊精，肝脏HMG-CoA还原酶的诱导与脂肪酸合酶（FAS）活性的降低同时发生。因此，可发酵碳水化合物的降胆固醇作用可能与脂肪生成的抑制有关，也与HDL1的加速清除有关，这与肝脏对胆固醇的需求增加有关。总之，可发酵碳水化合物可能有利于胆固醇的清除，并通过发挥比考来烯胺更复杂的生理作用而具有总体的降脂效果。
