Trautwein E A, Rieckhoff D, Erbersdobler H F
Institute of Human Nutrition and Food Science, University of Kiel, 24105 Kiel, Germany.
J Nutr. 1998 Nov;128(11):1937-43. doi: 10.1093/jn/128.11.1937.
The mechanisms by which inulin may elicit its lipid-lowering effect are not well elucidated. To examine the lipid-lowering potential of inulin and especially its effect on bile acid metabolism, male golden Syrian hamsters were fed semipurified diets containing 20 g/100 g fat, 0.12 g/100 g cholesterol and 0 (control), 8, 12 or 16% inulin for 5 wk. Plasma total cholesterol concentrations were significantly lowered by 18, 15 and 29% in hamsters fed 8, 12 and 16% inulin, respectively. Dietary inulin specifically decreased VLDL cholesterol, which was significantly lower in hamsters fed 16% inulin compared with controls (1.1 +/- 0.3 vs. 2.9 +/- 0.6 mmol/L). LDL and HDL cholesterol were not significantly affected by dietary inulin. Plasma triacylglycerol was significantly reduced by 40 and 63% in hamsters fed 12 and 16% inulin, respectively. Hepatic total cholesterol and particularly esterified cholesterol accumulation were significantly lower in hamsters fed 8% inulin compared with controls. All three levels of dietary inulin caused distinct alterations in the bile acid profile of gallbladder bile. Taurochenodeoxycholic acid was significantly lower, whereas glycocholic and glycodeoxycholic acid were greater in hamsters fed inulin. Daily fecal bile acid excretion (micromol/d) tended to be greater (P = 0.056) in inulin-fed hamsters compared with controls, whereas daily neutral sterol excretion was not affected. These data demonstrate that the lipid-lowering action of inulin is possibly due to several mechanisms, including altered hepatic triacylglycerol synthesis and VLDL secretion and impaired reabsorption of circulating bile acids.
菊粉发挥其降脂作用的机制尚未完全阐明。为了研究菊粉的降脂潜力，尤其是其对胆汁酸代谢的影响，将雄性金黄叙利亚仓鼠喂养含20 g/100 g脂肪、0.12 g/100 g胆固醇以及0（对照）、8%、12%或16%菊粉的半纯化日粮，持续5周。分别喂食8%、12%和16%菊粉的仓鼠血浆总胆固醇浓度显著降低了18%、15%和29%。日粮中的菊粉特异性降低了极低密度脂蛋白胆固醇（VLDL胆固醇），与对照组相比，喂食16%菊粉的仓鼠体内VLDL胆固醇显著更低（1.1±0.3 vs. 2.9±0.6 mmol/L）。低密度脂蛋白胆固醇（LDL胆固醇）和高密度脂蛋白胆固醇（HDL胆固醇）不受日粮菊粉的显著影响。分别喂食12%和16%菊粉的仓鼠血浆甘油三酯显著降低了40%和63%。与对照组相比，喂食8%菊粉的仓鼠肝脏总胆固醇，尤其是酯化胆固醇的积累显著更低。日粮中三种菊粉水平均导致胆囊胆汁的胆汁酸谱发生明显改变。喂食菊粉的仓鼠中牛磺鹅去氧胆酸显著更低，而甘胆酸和甘氨脱氧胆酸则更高。与对照组相比，喂食菊粉的仓鼠每日粪便胆汁酸排泄量（微摩尔/天）有增加趋势（P = 0.056），而每日中性固醇排泄不受影响。这些数据表明，菊粉的降脂作用可能归因于多种机制，包括肝脏甘油三酯合成和VLDL分泌的改变以及循环胆汁酸重吸收受损。
