Laboratories of Translational Medicine, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing 210028, PR China.
Food Funct. 2021 Sep 7;12(17):7709-7717. doi: 10.1039/d1fo01237a. Epub 2021 Jul 21.
Dietary fiber is the basic therapeutic method to relieve the symptoms of chronic constipation. The aim of this study was to compare the laxative effect of konjac glucomannan (KGM) and konjac oligosaccharides (KOS) on constipated rats. KGM and KOS were administered to loperamide-induced constipated rats at dosages of 100 mg per kg bw and 400 mg per kg bw for 15 days. Feces were collected to evaluate the defecation function. X-ray imaging and an electrophysiological system were used to determine gastrointestinal (GI) motility. Immunohistochemistry and western blotting were used to measure the protein levels. Magnetic resonance imaging (MRI) was performed to assess flatulence. Our results demonstrated that low-dose KOS (L-KOS) exerted the best laxative effect. Compared to the normal control (NC) group, the fecal number in the L-KOS group increased by 39.4%, and the fecal weight significantly increased by 31.9% which was higher than those in the low-dose KGM (L-KGM) and high-dose KGM (H-KGM) groups. The fecal moisture content and transit scores were significantly increased only in the L-KOS group. Meanwhile, less GI gas was produced by KOS. Additionally, further investigations suggested that KOS could upregulate the protein expression of stem cell factors (SCF)/c-kit, and significantly promoted the secretion of mucus. In conclusion, compared to KGM, KOS had a conspicuous laxative effect especially at a low dosage. The potential laxative mechanisms of KOS probably are regulating the SCF/c-kit signalling pathway and increasing mucus secretion. These findings indicated that as a kind of functional oligosaccharide, KOS is more conducive to alleviating constipation compared to polysaccharides.
膳食纤维是缓解慢性便秘症状的基本治疗方法。本研究旨在比较魔芋葡甘聚糖（KGM）和魔芋低聚糖（KOS）对便秘大鼠的通便作用。将 KGM 和 KOS 以 100mg/kg bw 和 400mg/kg bw 的剂量分别给予洛哌丁胺诱导的便秘大鼠，连续给药 15 天。收集粪便以评估排便功能。使用 X 射线成像和电生理系统来确定胃肠道（GI）运动。免疫组织化学和 Western blot 用于测量蛋白质水平。磁共振成像（MRI）用于评估胀气。结果表明，低剂量 KOS（L-KOS）具有最佳的通便作用。与正常对照组（NC）相比，L-KOS 组的粪便数量增加了 39.4%，粪便重量显著增加了 31.9%，高于低剂量 KGM（L-KGM）和高剂量 KGM（H-KGM）组。只有 L-KOS 组的粪便水分含量和转运评分显著增加。同时，KOS 产生的 GI 气体较少。此外，进一步的研究表明，KOS 可以上调干细胞因子（SCF）/c-kit 的蛋白表达，并显著促进粘液分泌。综上所述，与 KGM 相比，KOS 具有明显的通便作用，尤其是在低剂量时。KOS 的潜在通便机制可能是调节 SCF/c-kit 信号通路和增加粘液分泌。这些发现表明，作为一种功能性低聚糖，KOS 比多糖更有利于缓解便秘。
