目的:探究有幽门螺杆菌(Helicobacter pylori, H. pylori)感染家族史,发生和未发生H. pylori感染的儿童胃部菌群特点。方法:分别采集患儿胃体和胃窦的黏膜标本,通过标本DNA提取、16S核糖体DNA(ribosomal DNA,rDNA)V3-V4区域PCR扩增、高通量测序、数据处理等步骤后,得到胃部黏膜菌群分析结果,将结果中有H. pylori感染家族史的标本根据是否发生H. pylori感染分为感染组(n=18)和非感染组(n=24),比较两组间菌群的α和β多样性、菌群丰度变化等指标,找出差异菌群,并对菌群功能进行预测分析。结果:感染组与非感染组胃部菌群α多样性和β多样性之间差异有统计学意义(P<0.05), 感染组的菌群多样性要低于非感染组。菌群相对丰度方面,门水平占优势的主要有变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidetes)、放线菌门(Actinobacteria)和梭杆菌门(Fusobacteria);属水平上,非感染组中拟杆菌(Bacteroides)、普雷沃氏菌(Prevotella)、链球菌(Streptococcus)和奈瑟菌(Neisseria)为优势菌种。差异物种方面,通过LEfSe分析,发现非感染组中属水平的拟杆菌属等的相对丰度显著高于感染组。功能预测发现,拟杆菌属与一些氨基酸和维生素代谢、丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)、哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin, mTOR)信号通路、安沙霉素(ansamycin)的合成相关通路均呈显著正相关。结论:有H. pylori感染家族史的儿童中,发生H. pylori感染和未发生感染者的胃部菌群存在显著差异,拟杆菌可能与儿童是否发生H. pylori感染存在关联。

Objective: To explore the characteristics of gastric microbiota in children with and without (Helicobacter pylori, H. pylori) infection who had family history of H. pylori infection. Methods: Mucosal biopsy samples of the gastric corpus and gastric antrum were collected during the gastroscope. And the gastric mucosa flora’s information of the two groups of children were obtained after sample DNA extraction, PCR amplification of the 16S ribosomal DNA (rDNA) V3-V4 region, high-throughput sequencing and data processing. All the samples with family history of H. pylori infection were divided into two groups, the H. pylori infection group (n=18) and the H. pylori non-infection group (n=24). Then the α-, β-diversity and bacteria abundance of the gastric microbiota were compared between the H. pylori infection and non-infection groups at different taxonomic levels. The differential microbiota was found out by LEfSe analysis, and then the function of microbiota predicted using phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) method. Results: There was statistically significant difference in α-diversity (P<0.05) between the two groups, indicating that the H. pylori non-infection group had higher microbial richness than the H. pylori infection group. Moreover, the β-diversity was significantly different as well (P<0.05), which meant that the microbiota composition of the two groups was different. At the phyla level, Proteobacteria, Firmicutes, Bacteroides, Actinobacteria, and Fusobacteria were dominant in the two groups. At the genus level, Bacteroides, Prevotella, Streptococcus, and Neisseria, etc. were dominant in the H. pylori non-infected group. Meanwhile, Helicobacter and Haemophilus etc. were dominant in the H. pylori infected group. LEfSe analysis showed that the relative abundance of Bacteroides etc. at the genus level in the H. pylori non-infected group was significantly higher than that in the H. pylori infected group. Functional prediction showed that Bacteroides were positively correlated with amino acid and vitamin metabolism, mitogen-activated protein kinase (MAPK), mammalian target of rapamycin (mTOR) signaling pathway and ansamycin synthesis pathway. Conclusion: The gastric microbiota between H. pylori positive and H. pylori negative in children with family history of H. pylori infection is significant different. Some gastric microbiota, such as Bacteroides, may have a potential relationship with H. pylori infection in children.