基于肠道菌群靶点，燕麦β-葡聚糖对2型糖尿病大鼠的调控作用及其机制研究

The increase of incidence of type 2 diabetes has been an important public health issue. It has been researched that gut microbiota plays an important role in the development of type 2 diabetes. Gut microbiot which serves as a target provides a new direction for the control strategy of type 2 diabetes by nutrition intervention so as to change the metabolic physiology of host. It has been verified that oat β - glucose has prebiotics function as a soluble dietary fiber. But the effect to diabetes is less studied. This work aims to evaluate the relationship between oat β - glucose and the rats with type 2 diabetes from the gut microbiot's point of view. We propose an animal model by high fat diet combined low dose STZ, we also apply oat β - glucose to intervent rats under nomal and diabetes condition for 12 weeks, to reveal the effect of oat β - glucose to the rats under diabetes condition. We explore the control mechanism from the aspect of organ function, igut microbiota as so on. This work provides a theory and strategy basis for the control of type 2 diabetes from the aspect of nutrtion intervention.

2型糖尿病发病率持续增长，已经成为重要的公共卫生问题。研究发现，肠道菌群在2型糖尿病的发生发展中发挥着重要作用。以肠道菌群为靶点，通过营养干预改善肠道菌群，进而改变宿主的代谢生理，为糖尿病的调控策略探索提供了新方向。燕麦β-葡聚糖作为一种可溶性膳食纤维已经被证实了有益生元作用。但其对糖尿病是否具有调控作用还未见报道。本研究拟从肠道菌群出发，评价燕麦β-葡聚糖对2型糖尿病大鼠的调控作用。通过采用高脂膳食联合低剂量STZ建立动物模型，应用燕麦β-葡聚糖对正常和糖尿病大鼠干预12周，以明确燕麦β-葡聚糖对2型糖尿病大鼠的调控作用；从器官功能和肠道菌群结构等方面，探索其调控机制。从营养干预角度为2型糖尿病的防控提供理论和策略依据。

通过高脂饲料喂养4周联合低剂量链脲佐菌素（streptozotocin,STZ）2次注射雄性Sprague-Dawley大鼠建立2型糖尿病动物模型。对照组、燕麦β-葡聚糖低、高剂量干预组,糖尿病模型组。连续喂养10周，每天观察大鼠的大鼠生长、进食及活动情况，于第0周、第5周、第10周进行代谢实验，观察其进食量和尿量；进行肠道转运实验，观察肠道转运时间；取血，检测血糖和相关血液、血清炎症因子等；取粪便进行粪便菌群的平板培养及肠道菌群检测。采用 western blotting和免疫组化法检测骨骼肌胰岛素抵抗的和结肠粘膜屏障相关蛋白的表达情况。结果显示：燕麦β-葡聚糖可以改善2型糖尿病大鼠的空腹血糖水平、胰岛素抵抗水平及胰岛β细胞形态结构，其中高剂量燕麦β-葡聚糖干预效果明显。2型糖尿病大鼠的肠道菌群紊乱，肠黏膜屏障受到一定程度的损伤，燕麦β-葡聚糖可以改善2型糖尿病大鼠的肠道菌群结构和肠黏膜机械屏障、化学屏障和生物屏障的结构和功能，进而调节机体内由LPS所引起的炎症反应，进而对2型糖尿病病情的进展产生积极调控作用。本研究结果为燕麦β-葡聚糖作为防治糖尿病的临床营养辅助治疗提供一定的科学依据，同时为寻求安全有效的防治方案提供了理论依据。.