Hira Tohru, Ikee Asuka, Kishimoto Yuka, Kanahori Sumiko, Hara Hiroshi
Laboratory of Nutritional Biochemistry, Research Faculty of Agriculture, Hokkaido University,Kita-9, Nishi-9, Kita-ku,Sapporo060-8589,Japan.
Graduate School of Agriculture, Hokkaido University,Sapporo,Japan.
Br J Nutr. 2015 Jul 14;114(1):34-42. doi: 10.1017/S0007114514004322. Epub 2015 Feb 11.
Glucagon-like peptide-1 (GLP-1), which is produced and released from enteroendocrine L cells, plays pivotal roles in postprandial glycaemia. The ingestion of resistant maltodextrin (RMD), a water-soluble non-digestible saccharide, improves the glycaemic response. In the present study, we examined whether the continuous feeding of RMD to rats affected GLP-1 levels and glycaemic control. Male Sprague-Dawley rats (6 weeks of age) were fed an American Institute of Nutrition (AIN)-93G-based diet containing either cellulose (5 %) as a control, RMD (2.5 or 5 %), or fructo-oligosaccharides (FOS, 2.5 or 5 %) for 7 weeks. During the test period, an intraperitoneal glucose tolerance test (IPGTT) was performed after 6 weeks. Fasting GLP-1 levels were significantly higher in the 5 % RMD group than in the control group after 6 weeks. The IPGTT results showed that the glycaemic response was lower in the 5 % RMD group than in the control group. Lower caecal pH, higher caecal tissue and content weights were observed in the RMD and FOS groups. Proglucagon mRNA levels were increased in the caecum and colon of both RMD and FOS groups, whereas caecal GLP-1 content was increased in the 5 % RMD group. In addition, a 1 h RMD exposure induced GLP-1 secretion in an enteroendocrine L-cell model, and single oral administration of RMD increased plasma GLP-1 levels in conscious rats. The present study demonstrates that continuous ingestion of RMD increased GLP-1 secretion and production in normal rats, which could be stimulated by its direct and indirect (enhanced gut fermentation) effects on GLP-1-producing cells, and contribute to improving glucose tolerance.
胰高血糖素样肽-1(GLP-1)由肠内分泌L细胞产生并释放,在餐后血糖中起关键作用。摄入抗性麦芽糊精(RMD)这种水溶性不可消化糖类可改善血糖反应。在本研究中,我们检测了持续给大鼠喂食RMD是否会影响GLP-1水平和血糖控制。将雄性Sprague-Dawley大鼠(6周龄)喂食以美国营养学会(AIN)-93G为基础的日粮,其中分别含有作为对照的纤维素(5%)、RMD(2.5%或5%)或低聚果糖(FOS,2.5%或5%),持续7周。在试验期第6周后进行腹腔内葡萄糖耐量试验(IPGTT)。6周后,5% RMD组的空腹GLP-1水平显著高于对照组。IPGTT结果显示,5% RMD组的血糖反应低于对照组。在RMD和FOS组中观察到盲肠pH值较低、盲肠组织和内容物重量较高。RMD组和FOS组的盲肠和结肠中胰高血糖素原mRNA水平均升高,而5% RMD组的盲肠GLP-1含量增加。此外,在肠内分泌L细胞模型中,1小时的RMD暴露可诱导GLP-1分泌,并且单次口服RMD可使清醒大鼠的血浆GLP-1水平升高。本研究表明,持续摄入RMD可增加正常大鼠的GLP-1分泌和产生,这可能是由于其对产生GLP-1的细胞的直接和间接(增强肠道发酵)作用所刺激,并有助于改善葡萄糖耐量。