基于“脑-肠-菌”轴研究隔药饼灸通过5-HT信号系统对肠易激综合征大鼠肠黏膜屏障的调节机制

IBS is a functional gastrointestinal disease, because of the absence evidence in morphological and biochemical, it’s can not explain to the clinical symptoms, which shows complication pathogenesis. Early study put forward that brain-gut axis regulation disorder is the important pathologic basis of IBS. Recently, the pathological physiological function of gut microbiota and the relation between gut microbiota and brain-gut axis is attracting scientist’s eyes. New studies indicate that IBS is regulated by neuro-immune-endocrine network via “brain-gut-microbiota” axis. The dysfunctional of “brain-gut-microbiota” plays an important role on IBS Pathogenesis. Also studies shows that 5-HT signal system plays an important role on IBS too, and 5-HT is an key participating media of acupuncture and moxibustion regulation mechanism to dysfunctional of neuro-immune-endocrine network. Our studies identified herbal-cake-separated moxibustion have good effects on functional gastrointestinal disease via brain-gut axis. In this study, we use the correlation between brain-gut axis and gut microbiota as entry point, to explore the regulation effects on IBS gut microbiota, and reveal the regulation mechanism of Intestinal mucosal barrier of Herbal-cake-separated moxibustion on irritable bowel syndrome rats through 5-HT system based on “brain-gut-microbiota” Axis.

肠易激综合征( irritable bowel syndrome，IBS) 是一种功能性胃肠病，因其缺乏形态学和生物化学异常改变、不能以器质性疾病解释的临床症状，其发病机制复杂。以往认为脑肠轴调控紊乱是IBS 的重要病理基础。近年来，肠道菌群的重要病理生理作用及其与脑肠轴交互关系得到重视。最新研究表明，“脑-肠-菌”互动异常通过神经-免疫-内分泌网络调控造成恶性循环，在IBS 的发病中起到重要病理基础作用。在胃肠疾病中，5-HT信号系统又会发生明显改变，而5-HT等物质正是针灸调控IBS已经失常的神经-免疫-内分泌网络的中间介质。本课题组前期研究初步证实，隔药饼灸通过脑肠轴的双向通路治疗功能性胃肠病。本研究以脑肠轴与肠道菌群相关性为切入点，探讨隔药饼灸对IBS大鼠肠道菌群的调整作用，基于“脑-肠-菌”轴进一步揭示隔药饼灸通过5-HT信号系统对IBS大鼠肠黏膜屏障的调节机制。

本项目在良好的前期研究基础上，以IBS-D大鼠为受试对象，运用16S rDNA基因片段PCR、RFLP分析技术、1H-NMR代谢组学技术、HPLC-ECD、免疫组化、免疫荧光染色等多种生物技术手段，对大鼠结肠组织、粪便等进行检测，基于“脑-肠-菌”轴进一步阐明隔药饼灸通过5-HT 信号系统对 IBS大鼠肠黏膜屏障的调节机制。研究发现：（1）隔药饼灸可以使IBS-D大鼠代谢紊乱状态部分恢复正常，通过影响免疫应答，肠道屏障完整性、肠上皮细胞炎症、胆汁酸的重吸收等改善IBS的症状。（2）隔药饼灸可以调节大鼠肠道菌群的多样性，进而通过影响粘蛋白降解、免疫调节、内脏超敏反应、肠道炎症等来改善IBS-D的症状。（3）隔药饼灸可以通过提高肠黏膜机械屏障紧密连接相关蛋白Claudin、ZO-1的表达，改善肠黏膜通透性，降低血清内毒素水平。（4）隔药饼灸可以调节5-TH信号系统中主要蛋白及受体的表达，达到治疗IBS-D的目的。综上研究，证实隔药饼灸可以调节肠道菌群多样性以及特征性代谢物的表达、调节5-HT及相关受体含量，最终改善肠黏膜屏障达到治疗肠易激综合征的目的。