Department of Biochemistry and Molecular Biology, Basic Medical College, Qingdao University of Medicine, 38 Dengzhou Road, Qingdao 266021, PR China.
Wageningen University, Food Technology Department, 6708PB, Wageningen, the Netherlands.
Biomed Pharmacother. 2019 Oct;118:109393. doi: 10.1016/j.biopha.2019.109393. Epub 2019 Sep 2.
Diabetes mellitus is associated with gut microbiota disturbance and intestinal mucosal injuries. This study investigated the influence of propolis on the gut microbiota and intestinal mucosa in rats with diabetes.
Sprague-Dawley (SD) rats were randomly assigned to the control group, model group, and three propolis groups (supplemented with 80, 160, and 240 mg/kg·bw propolis, respectively). A high-fat diet combined with a streptozotocin (STZ) abdominal injection were used to induce diabetes in the rats. After 4 weeks, the intestinal histopathological analysis of the ileum was observed by transmission electron microscopy. The fasting blood glucose (FBG), plasma insulin, glucose tolerance (OGTT) and glycosylated hemoglobin (HbA1c) levels were measured. The expression of tight junction (TJ) proteins in the ileum was measured using western blotting. The molecular ecology of the fecal gut microbiota was analyzed by 16S rDNA high-throughput sequencing. The contents of the short-chain fatty acids (SCFAs) in feces were measured using high-performance liquid chromatography (HPLC).
After propolis treatment, compared to the model group, FBG and HbA1c levels declined, while the glucose tolerance and insulin sensitivity index (ISI) increased. The levels of TJ proteins in the ileum increased in the propolis groups. The tight junctions and gap junctions of the intestinal epithelium were also improved in the propolis groups. The contents of the feces acetic acid, propionic acid and butyrate were increased in the propolis groups. 16S rDNA high-throughput sequencing revealed that the composition of the gut microbiota of rats in the propolis supplement group was significantly improved.
Compared to the model group, propolis exerted hypoglycemic effects in diabetic rats, and it repaired intestinal mucosal damage, benefited the communities of the gut microbiota and increased SCFA levels in diabetic rats.
糖尿病与肠道微生物群紊乱和肠黏膜损伤有关。本研究探讨了蜂胶对糖尿病大鼠肠道微生物群和肠黏膜的影响。
将 Sprague-Dawley（SD）大鼠随机分为对照组、模型组和 3 个蜂胶组（分别补充 80、160 和 240mg/kg·bw 蜂胶）。采用高脂饮食联合链脲佐菌素（STZ）腹腔注射诱导大鼠糖尿病。4 周后，通过透射电子显微镜观察回肠的肠道组织病理学分析。测量空腹血糖（FBG）、血浆胰岛素、葡萄糖耐量（OGTT）和糖化血红蛋白（HbA1c）水平。使用蛋白质印迹法测量回肠中紧密连接（TJ）蛋白的表达。通过 16S rDNA 高通量测序分析粪便肠道微生物群的分子生态学。使用高效液相色谱法（HPLC）测量粪便中短链脂肪酸（SCFAs）的含量。
与模型组相比，蜂胶治疗后 FBG 和 HbA1c 水平降低，而葡萄糖耐量和胰岛素敏感指数（ISI）增加。回肠 TJ 蛋白水平在蜂胶组中升高。蜂胶组的肠上皮紧密连接和间隙连接也得到改善。蜂胶组粪便中乙酸、丙酸和丁酸的含量增加。16S rDNA 高通量测序显示，蜂胶补充组大鼠肠道微生物群的组成得到显著改善。
与模型组相比，蜂胶在糖尿病大鼠中发挥降血糖作用，修复肠黏膜损伤，有利于肠道微生物群的群落结构，并增加糖尿病大鼠中 SCFA 的水平。
