过敏性紫癜患儿肠道菌群的构成和多样性与其肠短链脂肪酸水平和肠屏障变化的相关性研究

Henoch-Schonlein purpura（HSP）is one of more commoner diseases in childhood.Its morbidity is in increase gradually. The pre-study of our group found that there were gut microbiota dysbiosis and intestinal barrier's damages in children with HSP. But the more deeper study could be not developed to explicit the effect of the composition and diversity of the gut microbiota on the gut short chain fatty acides（SCFAs）and the intestinal barriers in the patients. At present, this kind of study is still not reported at home and abroad. In the study, the samples of the feces and blood will be collected from the control group and children with abdominal and non-abdominal type of HSP. In order to explicit the composition and diversity of the gut microbiota,the gut microbiota in faecal samples will be investigated by the high-throughput sequencing approaches, and according to the sequencing, some special bacteria will be had quantity analysis by the real-time PCR. In order to explicit the changes of the intestinal metabolic substances, the concentration of SCFAs in the faecal samples will be measured by the gas chromatography-mass spectrometry analysis. In order to explicit the changes of the intestinal barriers, SIgA in faecal samples and some cytokines in the blood will be measured by the immune methods, and the level of endotoxin, diamine oxidase, D-lactose, vasoactive intestinal peptide, substance P and gastrin in the blood will be measured by the biochemical and radioimmune methods respectively. In order to explicit the correlationship among composition and diversity of gut microbiota, gut SCFAs and intestinal barriers in children with HSP, the above material and data will be used and analysed by the statistical methods. It will be believed that the study results have an important role on novel understanding causes, pathogenesis, treatment, prevention and prognosis evaluation for children with HSP.

过敏性紫癜（HSP）是发病逐年在增加危害儿童的多发病。课题组前期研究发现HSP患儿有肠道菌群失调和肠屏障损伤，但未能深入研究和明确HSP患儿肠道菌群的构成和多样性与其肠短链脂肪酸（SCFAs）和肠屏障的相关性，此类研究国内外仍未见报道。 本研究收集对照组、HSP腹型和非腹型患儿治疗过程中的粪便和血液标本，用高通量测序技术测粪便肠道菌群谱，对有特殊分布的细菌行荧光定量PCR分析，以明确患儿肠道菌群的构成和多样性；用气相色谱方法测粪便中SCFAs水平，以明确患儿肠代谢物的变化；用免疫法测粪便中SIgA和血细胞因子水平；用生物化学和放射免疫法测血中内毒素、二胺氧化酶、D-乳酸、血管活性肽、P-物质和胃泌素水平，以明确患儿肠屏障的变化；用统计学方法研究和综合分析对照组和患儿肠道菌群多样性与其肠SCFAs水平和肠屏障的相关性。其结果对更新认识HSP的病因、发病机制、防治和预后评估有重要的指导作用。

研究背景和内容：过敏性紫癜（HSP）是发病逐年在增加危害儿童的多发病。本研究收集对照组(A组)、HSP患儿治疗急性期（B组）和恢复期（C组）中的粪便和血液标本，用高通量测序技术测粪便肠道菌群谱，对有特殊分布的细菌行荧光定量PCR分析，以明确患儿肠道菌群的构成和多样性；用气相色谱方法测粪便中SCFAs水平，以明确患儿肠代谢物的变化；用免疫法测粪便中SIgA和血细胞因子水平；用生物化学和放射免疫法测血中内毒素、二胺氧化酶、D-乳酸、血管活性肽、P-物质和胃泌素水平，以明确HSP患儿肠屏障的变化；研究和分析对照组和患儿肠道菌群多样性与其肠SCFAs水平和肠屏障的相关性。结果： 1）B组患儿拟杆菌门、变形杆菌门显著增加，厚壁菌门及未分类菌门显著减少；在属水平，主要表现在拟杆菌门、变形杆菌门、厚壁菌门及未分类菌门下的属水平；HSP患儿肠道菌群失调明显存在。2）B组患儿粪肠乙酸、丁酸水平是显著降低的，C组患儿乙酸向正常水平回升，丁酸仍显著低于A组。3）B组患儿粪肠内CA、CDCA表现为减少的趋势，DCA、LCA显著减少；C组患儿粪肠CA、CDCA显著增加，DCA、LCA显著减少。4）B组患儿乙酸、丁酸、次级胆汁酸减少伴随的减少的细菌属及增加的细菌属；C组患儿丁酸、次级胆汁酸减少与初级胆汁酸增加伴随的减少的细菌属及增加的细菌属。5）HSP患儿粪便中sIgA 含量是增高的；HSP患儿血浆中二胺氧化酶、D-乳酸及内毒素含量升高。6）B组患儿血浆和粪便中VIP、SP和5-HT水平较对照组明显升高；C组患儿血浆和粪便中VIP、SP和5-HT水平较急性期组降低；B组患儿血浆和粪便中GAS水平较对照组明显减低。而C组患儿血浆和粪便中GAS水平较急性期增高。7）B组患儿Th17、Th17/Treg及IL-17、IL-23水平高于正常对照组，C组患儿较B组患儿降低；B组患儿Treg水平低于A组，C组患儿较B组患儿升高。8）IL-6、IL-8、IL-17、IL-23、TNF-αHSP患儿组水平均高于A组；IFN-γHSP患儿组水平均低于A组。科学意义：其结果对更新认识HSP的病因、发病机制、防治和预后评估有重要的指导性。