白术-木香药对对脾虚腹泻型肠易激综合征大鼠肠道菌群与短链脂肪酸代谢的调节作用

Regulatory effects of couplet medicinals of Atractylodes macrocephala-Aucklandia lappa on gut microbiota and short-chain fatty acid metabolism in the irritable bowel syndrome rat with spleen deficiency and diarrhea

目的 探讨白术-木香药对对脾虚腹泻型肠易激综合征(IBS-D)大鼠肠道菌群与短链脂肪酸(SCFAs)代谢的调节作用。方法 使用番泻叶灌胃联合束缚刺激构建大鼠脾虚IBS-D模型。将造模成功的大鼠分为模型组、阳性对照组(匹维溴铵1.5 mg/kg)和白术-木香药对低、中、高剂量组(0.7、1.4、2.8 g/kg),每组6只;另取6只健康大鼠作为空白对照组。空白对照组与模型组大鼠灌胃生理盐水,其余各组灌胃相应药液,每天1次,连续14 d。观察大鼠一般状况,并检测粪便含水量;检测大鼠肠道敏感性[以腹壁撤退反射(AWR)阈值评价]和肠道推进率;检测大鼠血清中5-羟色胺(5-HT)、P物质(SP)水平;观察大鼠结肠组织病理变化,检测大鼠结肠组织中5-HT3受体(5-HT3R)、5-HT4受体(5-HT4R)、5-HT转运体(SERT)蛋白表达水平。取空白对照组、模型组和白术-木香药对高剂量组大鼠粪便样本进行16S rRNA测序分析,并检测粪便中乙酸、丙酸、丁酸的含量。结果 与模型组比较,白术-木香药对中、高剂量组大鼠给药7、14 d后的体重,粪便含水量,AWR阈值,结肠组织中5-HT4R、SERT蛋白表达水平均显著升高(P<0.05或P<0.01);血清中5-HT、SP水平,肠道推进率(白术-木香药对中剂量组除外),结肠组织中5-HT3R蛋白表达水平均显著降低(P<0.01);腹泻缓解,精神状态恢复,结肠组织部分结构恢复;且白术-木香药对高剂量组大鼠肠道菌群的多样性与物种数量有所减少,粪便中丁酸含量显著降低(P<0.05)。结论 白术与木香配伍可以改善脾虚IBS-D模型大鼠的肠道动力及肠道敏感性,并缓解腹泻,这可能与改善肠道菌群结构变化,降低5-HT表达和丁酸含量以及升高5-HT4R、SERT表达有关。

OBJECTIVE To investigate the regulatory effects of couplet medicinals of Atractylodes macrocephala-Aucklandia lappa on gut microbiota and short-chain fatty acids(SCFAs)in the diarrhea-type irritable bowel syndrome(IBS-D)rats with spleen deficiency.METHODS The IBS-D rat model with spleen deficiency was induced by intragastric administration of Senna alexandrina combined with restraint stimulation.The model rats were divided into model group,positive control group(pinaverium bromide 1.5 mg/kg),A.macrocephala-A.lappa low-dose,medium-dose and high-dose groups(0.7,1.4,2.8 g/kg),with 6 rats in each group.Another 6 healthy rats were taken as the blank control group.The blank control group and the model group were given normal saline intragastrically,and other groups were given relevant drug liquid intragastrically,once a day,for consecutive 14 days.The general characteristics of rats and fecal water content were observed,and intestinal sensitivity[evaluating by abdominal wall withdrawal reflex(AWR)threshold]and the intestinal propulsion rate were determined.The serum levels of 5-hydroxytryptamine(5-HT)and SP were detected,and the pathological changes of colon tissue were observed;the protein expressions of 5-HT-3 receptor(5-HT3R),5-HT4R and 5-HT transporter(SERT)in colon tissue of rats were detected.16S rRNA sequencing was performed for the feces of rats in blank control group,model group and A.macrocephala-A.lappa high-dose group;the contents of acetic acid,propionic acid and butyric acid in the feces of the rats were determined.RESULTS Compared with the model group,the body weight after 7 and 14 days of medication,fecal water content,AWR threshold,and the protein expressions of 5-HT4R and SERT in colon tissue were increased significantly in the A.macrocephala-A.lappa medium-dose and high-dose groups(P<0.05 or P<0.01);serum contents of 5-HT and SP,intestinal propulsion rate(except for A.macrocephala-A.lappa medium-dose group),the protein expression of 5-HT3R in colon tissue were decreased significantly(P<0.01);diarrhea relief,mental state recovery,and partially recovery of the structure of colon tissue were all found;moreover,the diversity and species number of gut microbiota were reduced in A.macrocephala-A.lappa high-dose group and the content of butyric acid in fecal samples was significantly reduced(P<0.05).CONCLUSIONS The compatibility of A.macrocephala and A.lappa can improve intestinal motility and sensitivity of IBS-D model rats with spleen deficiency,and alleviate diarrhea.This may be related to improving changes in intestinal microbiota structure,reducing 5-HT expression and butyric acid content,and increasing 5-HT4R and SERT expression.