[Effect of electroacupuncture at different acupoint combination on intestinal inflammatory response and intestinal flora in obese rats].

Abstract

To observe the effect of electroacupuncture (EA) at different acupoint combination on intestinal inflammatory response, intestinal flora structure and metabolic function in obese rats. 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. 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). 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.