Objective: To observe the effect of electroacupuncture (EA) at different acupoint combination on intestinal inflammatory response, intestinal flora structure and metabolic function in obese rats.
Methods: Ninety male Wistar rats aged 8 weeks were collected. Ten rats were randomly collected from 15 rats fed with regular forage in a normal group and the rest 75 rats were fed with high-fat forage to induce obesity models. Forty rats were modeled successfully and randomized into a model group, a lower-limb EA group, an abdomen EA group and a biaoben acupoints group, 10 rats in each one. "Zusanli" (ST 36) and "Fenglong" (ST 40) were selected in the lower-limb EA group, "Zhongwan "(CV 12), "Tianshu "(ST 25) and "Guanyuan" (CV 4) were selected in the abdomen EA group. The acupoint prescriptions in the above two groups were combined in the biaoben acupoints group. EA was delivered in all of the intervention groups, with continuous wave, 2 Hz in frequency and 1 mA in current intensity. The intervention was administered three times weekly (on Monday, Wednesday and Friday), for consecutive 8 weeks. Before intervention and on the last day of the 8th week of intervention, the body weight and 24 h food intake were observed. After intervention, using Western blot method, the proteins expressions of interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) were detected in the tissue of the small intestine; 16S rRNA sequencing technology was adopted to detect the distribution structure and metabolic function of intestinal flora.
Results: Compared with the normal group, the body weight, the food intake and the proteins expressions of IL-6 and TNF-α in small intestine were all increased in the model group (P<0.01). The above indexes of each EA intervention group were all decreased (P<0.01) when compared with the model group. The proteins expressions of IL-6 and TNF-α in the small intestine tissue of rats in biaoben acupoints group were lower than those in the other two EA intervention groups (P<0.01). Compared with the normal group, the ratio of Firmicutes/Bacteroidetes was elevated (P<0.01), while the abundance of Lactobacillus, Muribaculaceae and Bifidobacteria decreased in the model group (P<0.01). When compared with the model group, the ratio of Firmicutes/Bacteroidetes in each EA intervention group was reduced (P<0.01) and the abundance of Lactobacillus, Bifidobacteria and Bacteroidetes increased (P<0.01). Compared with the other two EA intervention groups, the abundance of Lactobacillus and Muribaculaceae was increased (P<0.01), while the abundance of Collinsella and Ruminococcus Gauvreauii reduced (P<0.01) in the biaoben acupoints group. In the model group, the abundance of clusters of orthologous groups of proteins (COG) function of intestinal flora in the transportation and metabolism of carbohydrate, amino acid and lipid, as well as in the signal transduction mechanisms were reduced when compared with the normal group (P<0.01). In comparison with the model group, the abundance of the above COG function was increased in each EA intervention group (P<0.01, P<0.05).
Conclusion: Electroacupuncture at biaoben acupoint combination may attenuate intestinal inflammatory response and effectively improve the structure and function of intestinal flora. The effect is superior to the intervention at the acupoints on the lower limbs and those on the abdomen, better regulating the abundance of specific intestinal flora.
目的：观察不同腧穴配伍电针干预对肥胖大鼠肠道炎性反应、肠道菌群结构及其代谢功能的影响。方法：90只8周龄雄性Wistar大鼠，从15只普通饲料喂养大鼠中随机选取10只分入正常组，余下75只大鼠采用高脂饲料诱导肥胖大鼠模型，将造模成功的40只大鼠随机分为模型组、下肢电针组、腹部电针组和标本配穴组，每组10只。下肢电针组穴取“丰隆”“足三里”，腹部电针组穴取“中脘”“天枢”“关元”，标本配穴组选取以上两组穴位，均进行电针干预，予连续波，频率2 Hz，电流强度1 mA，每周（周一、三、五）干预3次，共干预8周。于干预前、干预第8周的最后1 d检测大鼠体质量和24 h进食量；干预后，采用Western blot法检测大鼠小肠组织白细胞介素6（IL-6）、肿瘤坏死因子α（TNF-α）蛋白表达；采用16S rRNA测序技术检测肠道菌群的分布结构和代谢功能。结果：与正常组比较，模型组大鼠体质量、进食量及小肠组织IL-6、TNF-α蛋白表达升高（P<0.01）；与模型组比较，各电针干预组以上指标均降低（P<0.01）；标本配穴组小肠组织IL-6、TNF-α蛋白表达低于其他电针干预组（P<0.01）。与正常组比较，模型组厚壁菌门/拟杆菌门比值升高（P<0.01），乳酸菌属、Muri菌属、双歧杆菌属丰度降低（P<0.01）；与模型组比较，各电针干预组厚壁菌门/拟杆菌门比值降低（P<0.01），乳酸菌属、双歧杆菌属、拟杆菌属丰度升高（P<0.01）；与其余电针干预组比较，标本配穴组乳酸菌属、Muri菌属丰度升高（P<0.01），柯林斯菌属和高氏瘤胃球菌属丰度降低（P<0.01）。与正常组比较，模型组肠道菌群蛋白直系同源簇（COG）功能在碳水化合物、氨基酸、脂质运输和代谢，信号转导机制方面的丰度均降低（P<0.01）；与模型组比较，各电针干预组COG功能以上方面的丰度均升高（P<0.01，P<0.05）。结论：标本配穴电针干预能减轻肥胖大鼠的肠道炎性反应，有效改善肠道菌群结构及功能，作用优于单纯下肢配穴及腹部配穴电针干预，能更好调节肠道特定菌群的丰度。.
Keywords: acupoint combination; electroacupuncture; inflammatory response; intestinal flora; obesity.