| Objective The aim of this study is to find out differential biomarkers of gastric mucosal lesions which can provide a new way for the prevention and treatment of gastric mucosal diseases,based on investigation of correlation between microbial changes and mucosal lesions in gastric,the relationship between Hp infection with gastric mucosal lesions and gastric microbiota.Methods The mucosa biopsy from gastric antrum and body of patients with chronic superficial gastritis,chronic atrophic gastritis,peptic ulcer and total micobial DNA has been extracted.Using total bacterial DNA as a template,the full length 16 S r RNA was amplified by using bacterial specific primer.The PCR products were sequenced for three generations in the Pac Bio SMRT platform.After the data were qualified,OTUs clustering,analysis and species annotation were performed.Alpha diversity was analyzed by drawing Observed curve,Chao 1 curve,Shannon Curve,Simpson curve and Rank abundance curve.PCo A and NMDS were used to compare the beta diversity of bacterial community structure.LEf Se analysis was used to find out the significant difference strains among the three groups.The dominant genera in different groups was selected according to their abundance,establishment the network of dominant species in the stomach.All data were type into the Epidata database to manage.Results A total of 145 samples of gastric antrum and corpus mucosa were collected and specimen bank of gastric mucosal flora in gastric diseases was established by using Epidata 3.1 software.41 qualified samples were obtained after total bacterial DNAextraction,PCR amplification,pre-sequencing and three-generation sequencing.After sequencing,by data quality control.There were 21 samples of chronic superficial gastritis(antrum tissue 13,corpus tissue 8;Hp positive 13,Hp negative 8),12 samples of chronic atrophic gastritis(antrum tissue 9,corpus tissue 3;Hp positive 9,Hp negative 3),8 samples of peptic ulcer(gastric ulcer 3,pylorus ulcer 1,duodenum ulcer 4;Hp positive 7,Hp negative 1).The data were used for bio-information analysis.The alpha diversity analysis shows that the both sample size and the sequencing volume meet the requirement of the following experimental data analysis.When the same amount of sequencing have been extracted from samples,the abundance,diversity and evenness of the peptic ulcer were lower than those of chronic superficial gastritis and chronic atrophic gastritis.The OTUs were annotated to each taxonomic level,30 phyla,more than 200 genera,and more than 300 species were identified.At the level of phyla,the dominant phylum were Proteobacteria,Fimicutes,Bacteroidetes and Actinobacteria.The dominant phylum of gastric flora in patients with peptic ulcer was significantly less than that in patients with chronic superficial gastritis and chronic atrophic gastritis.With the aggravation of gastric mucosa inflammation,the dominant bacteria of gastric flora gradually decreased and the abundance of Helicobacter gradually increased at genus level.At species level,220 chronic superficial gastritis,122 chronic atrophic gastritis and 49 peptic ulcer cases were identified separately and the level of gastric flora in patients with peptic ulcer was significantly reduced,and Helicobacter pylori became the dominant species.Beta diversity analysis of bacterial community structure revealed that there were significant differences between peptic ulcer with chronic superficial gastritis and chronic atrophic gastritis groups.However,there was no significant difference between chronic superficial gastritis and chronic atrophic gastritis,gastric antrum and corpus,Hp-and Hp+groups.Lefse analysis showed that a total of 41 strains were found significantly different in these three groups.Network reveals a complex microecological interaction in the stomach.Conclusion Similar with the gut microecology,the stomach is also a complexmicrobial community in which species interaction maintain the stability of the stomach microecology;with the aggravation of gastric mucosal lesions,the abundance and diversity of bacteria in the gastric reduced gradually;the bacteria in the patient’s gastric with peptic ulcer were significantly lower than those in patients with chronic gastritis,and Hp becomes absolute dominant;with the increasing degree of mucosal inflammation the beneficial strains decreased gradually.The oral supplementation of probiotics provides a new therapeutic approach for prevent and treat gastric mucosal lesions. |
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