胃黏膜菌群在胃癌发生过程中的动态变化研究

Study on Dynamic Changes of Gastric Mucosal Flora during the Occurrence of Gastric Cancer

目的:探讨胃黏膜菌群在胃癌(GC)发生过程中的动态变化。方法:收集浅表性胃炎(SG)患者8例、萎缩性胃炎(AG)患者9例、肠化生及异型增生(IM/DYS)患者12例和GC患者14例,采用16S rDNA基因高通量测序技术检测GC患者和胃癌前病变患者胃黏膜菌群,通过未观测状态重建的群落系统发育研究(PICRUSt)预测菌群的功能差异。结果:在门水平上,4组样本的胃黏膜菌群丰度排名前5的类别组成相同,但占比有所差异,由SG进展到GC的过程中,变形菌门、放线菌门丰度呈减少趋势,厚壁菌门、拟杆菌门丰度呈增加趋势;在属水平上,从SG发展到GC,普氏菌属及乳杆菌属丰度比例不断增高,螺杆菌属丰度比例在GC组中最低,同时发现GC组中乳杆菌属、戴阿利斯特杆菌属、巨球型菌属、微单胞菌属、凝聚杆菌属明显富集;线性判别(LEfSe)分析结果显示,SG组的优势菌属为细菌,IM/DYS组的优势菌属为微红微球属、红杆菌科、弓形菌属,GC组优势菌属为红蝽菌科;KEGG未富集到差异显著的代谢通路。结论:GC患者胃黏膜菌群群落及多样性与癌前病变组存在明显差异;GC发生过程中菌群的生态失调。

Objective:To explore the dynamic changes of gastric mucosal flora in the occurrence of gastric cancer(GC).Methods:8 patients with superficial gastritis(SG),9 patients with atrophic gastritis(AG),12 patients with intestinal metaplasia and dysplasia(IM/DYS),and 14 patients with GC were collected.High-throughput sequencing of the 16S rDNA gene was used to detect the gastric mucosal flora of GC patients and patients with gastric precancerous lesions.The functional differences of microbiota were predicted by phylogenetic investigation of communities by reconstruction of unobserved states(PICRUSt).Results:At the phylum level,the composition of the top five most abundant bacterial flora was the same among the four groups,but the proportions were different.During the process from SG to GC,the abundance of Proteobacteria and Actinobacteria showed a decreasing trend,while that of Firmicutes and Bacteroidetes showed an increasing trend.At the genus level,the abundance of Prevotella and Lactobacillus increased from SG to GC,and the abundance of Helicobacter reached the lowest in the GC group.Meanwhile,Lactobacillus,Dealisteria,Macrococcus,Micromononas,and Condensates were significantly enriched in the GC group.LefSe analysis showed that Bacteria was the dominant genus in the SG group,while Rubellimicrobium,Rhodobacteraceae,and Arcobacter were the dominant genera in the IM/DYS group.Coriobacteriaceae was the dominant genus in the GC group,and no significantly different metabolic pathways were enriched in KEGG.Conclusion:There are significant differences in the community and diversity of gastric mucosa flora between GC patients and precancerous lesions.