Key Laboratory of Acupuncture and Immunological Effects, Shanghai University of Traditional Chinese Medicine, Shanghai 200030, China.
Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, United States.
World J Gastroenterol. 2019 Aug 28;25(32):4696-4714. doi: 10.3748/wjg.v25.i32.4696.
About one-third of refractory irritable bowel syndrome (IBS) cases are caused by gastrointestinal (GI) infection/inflammation, known as post-infectious/post-inflammatory IBS (PI-IBS). Although it is known that intestinal microbiota and host NOD-like receptor family pyrin domain containing 6 (NLRP6) inflammsome signaling are closely related to PI-IBS and moxibustion has a therapeutic effect on PI-IBS, whether moxibustion regulates the intestinal flora and host NLRP6 events in PI-IBS remains unclear.
To examine the regulatory effect of moxibustion on intestinal microbiota and host NLRP6 inflammatory signaling in PI-IBS.
Sprague-Dawley rats were divided into a normal control group, a model control group, a mild moxibustion group, and a sham mild moxibustion group. PI-IBS rats in the mild moxibustion group were treated with moxibusiton at bilateral Tianshu (ST 25) and Zusanli (ST36) for 7 consecutive days for 10 min each time. The sham group rats were given the same treatment as the mild moxibustion group except the moxa stick was not ignited. Abdominal withdrawal reflex (AWR) score was measured to assess the visceral sensitivity, and colon histopathology and ultrastructure, colonic myeloperoxidase (MPO) activity, and serum C-reactive protein (CRP) level were measured to evaluate low-grade colonic inflammation in rats. The relative abundance of selected intestinal bacteria in rat feces was detected by 16S rDNA PCR and the NLRP6 inflammsome signaling in the colon was detected by immunofluorescence, qRT-PCR, and Western blot.
The AWR score was significantly decreased and the low-grade intestinal inflammation reflected by serum CRP and colonic MPO levels was inhibited in the mild moxibustion group compared with the sham group. Mild moxibustion remarkably increased the relative DNA abundances of , , and but decreased that of in the gut of PI-IBS rats. Additionally, mild moxibustion induced mRNA and protein expression of intestine lectin 1 but inhibited the expression of IL-1β, IL-18, and resistance-like molecule β by promoting the NLRP6 and reducing the mRNA and protein expression of apoptosis-associated speck-like protein containing CARD (ASC) and cysteinyl-aspartate-specific proteinase 1 (Caspase-1). The relative DNA abundances of , , , and in each group were correlated with the mRNA and protein expression of NLRP6, ASC, and Caspase-1 in the colon.
These findings indicated that mild moxibustion can relieve low-grade GI inflammation and alleviate visceral hypersensitivity in PI-IBS by regulating intestinal microbes and controlling NLRP6 inflammasome signaling.
约三分之一的难治性肠易激综合征（IBS）病例是由胃肠道（GI）感染/炎症引起的，称为感染后/炎症后肠易激综合征（PI-IBS）。虽然已知肠道微生物群和宿主 NOD 样受体家族 pyrin 域包含 6（NLRP6）炎症小体信号与 PI-IBS 密切相关，并且艾灸对 PI-IBS 具有治疗作用，但艾灸是否调节 PI-IBS 中的肠道菌群和宿主 NLRP6 事件尚不清楚。
研究艾灸对 PI-IBS 中肠道微生物群和宿主 NLRP6 炎症信号的调节作用。
将 Sprague-Dawley 大鼠分为正常对照组、模型对照组、温和艾灸组和假温和艾灸组。温和艾灸组的 PI-IBS 大鼠连续 7 天每天双侧天枢（ST 25）和足三里（ST36）艾灸 10 分钟。假温和组大鼠给予与温和艾灸组相同的治疗，但不点燃艾条。通过腹壁退缩反射（AWR）评分评估内脏敏感性，通过结肠组织病理学和超微结构、结肠髓过氧化物酶（MPO）活性和血清 C-反应蛋白（CRP）水平评估大鼠的低度结肠炎症。通过 16S rDNA PCR 检测大鼠粪便中选定肠道细菌的相对丰度，通过免疫荧光、qRT-PCR 和 Western blot 检测结肠中的 NLRP6 炎症小体信号。
与假温和组相比，温和艾灸组 AWR 评分显著降低，血清 CRP 和结肠 MPO 水平反映的低度肠道炎症受到抑制。温和艾灸显著增加了 PI-IBS 大鼠肠道中、、和的相对 DNA 丰度，但降低了的相对 DNA 丰度。此外，温和艾灸通过促进 NLRP6 和降低凋亡相关斑点样蛋白含有 CARD（ASC）和半胱天冬氨酸特异性蛋白酶 1（Caspase-1）的 mRNA 和蛋白表达，诱导肠上皮 1 的 mRNA 和蛋白表达，但抑制 IL-1β、IL-18 和抗性样分子 β 的表达。各组的相对 DNA 丰度与结肠中 NLRP6、ASC 和 Caspase-1 的 mRNA 和蛋白表达相关。
这些发现表明，温和艾灸通过调节肠道微生物群和控制 NLRP6 炎症小体信号，可缓解 PI-IBS 中的低度胃肠道炎症并减轻内脏高敏性。
