Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University , Guangzhou 510642, China.
J Agric Food Chem. 2017 Mar 1;65(8):1556-1565. doi: 10.1021/acs.jafc.6b05320. Epub 2017 Feb 17.
Konjac gel foods that mainly consist of deacetylated konjac glucomannan (Da-KGM) are considered to have the same health benefits as native konjac glucomannan (KGM); however, no definitive data support this notion. The objective of this study was to compare the effects of Da-KGM and KGM on the hyperlipidemia and liver steatosis induced by high-fat diet feeding and to investigate the underlying molecular mechanisms. C57BL/6 mice were fed (1) normal chow diet, (2) high-fat diet, (3) HFD with KGM, or (4) HFD with Da-KGM for 10 weeks. KGM, but not Da-KGM, showed decreased fat accumulation, improved blood and liver lipid profiles, and prevention of liver lipid droplet deposition compared with HFD. Compared with Da-KGM, KGM increased the outputs of fecal bile acid (KGM 22.5 ± 2.34 mg/g vs Da-KGM 19.3 ± 1.87 mg/g), fat (KGM 5.56 ± 0.68 mg/g vs Da-KGM 4.42 ± 0.57 mg/g) and cholesterol (KGM2.67 ± 0.43 mg/g vs Da-KGM 1.78 ± 0.28 mg/g), fecal concentrations of total short-chain fatty acids (KGM 103 ± 14.8 μmol/g vs Da-KGM 74.5 ± 8.49 μmol/g), and improved hepatic antioxidant status and upregulated CYP7A1 and LDLR gene expression. These findings suggest that deacetylation of KGM negatively affects its fermentation characteristics and its inhibition of lipid absorption, which thereby reduces Da-KGM's health benefits.
主要由去乙酰化魔芋葡甘露聚糖（Da-KGM）组成的魔芋凝胶食品被认为具有与天然魔芋葡甘露聚糖（KGM）相同的健康益处；然而，没有明确的数据支持这一观点。本研究旨在比较 Da-KGM 和 KGM 对高脂肪饮食喂养引起的高血脂和肝脂肪变性的影响，并探讨其潜在的分子机制。C57BL/6 小鼠分别用（1）正常饲料、（2）高脂肪饲料、（3）KGM 高脂肪饲料或（4）Da-KGM 高脂肪饲料喂养 10 周。与 HFD 相比，KGM 而非 Da-KGM 显示出脂肪积累减少、改善了血液和肝脏脂质谱以及防止肝脂质滴沉积。与 Da-KGM 相比，KGM 增加了粪便胆汁酸的排出量（KGM 22.5 ± 2.34 mg/g 比 Da-KGM 19.3 ± 1.87 mg/g）、脂肪（KGM 5.56 ± 0.68 mg/g 比 Da-KGM 4.42 ± 0.57 mg/g）和胆固醇（KGM2.67 ± 0.43 mg/g 比 Da-KGM 1.78 ± 0.28 mg/g），粪便短链脂肪酸总浓度（KGM 103 ± 14.8 μmol/g 比 Da-KGM 74.5 ± 8.49 μmol/g），改善了肝脏抗氧化状态并上调了 CYP7A1 和 LDLR 基因表达。这些发现表明，KGM 的去乙酰化会对其发酵特性和脂质吸收抑制产生负面影响，从而降低 Da-KGM 的健康益处。
