Changes in Gastric Corpus Microbiota With Age and After Helicobacter pylori Eradication: A Long-Term Follow-Up Study

Helicobacter pyloriinfection changes gastric microbiota profiles. However, it is not clear whetherH. pylorieradication can restore the healthy gastric microbiota. Moreover, there has been no study regarding the changes in gastric microbiota with aging. The objective of this study was to investigate the changes in gastric corpus microbiota with age and followingH. pylorieradication. Changes in corpus mucosa-associated microbiota were evaluated in 43 individuals with endoscopic follow-up > 1 year, including 8H. pylori-uninfected and 15H. pylori-infected subjects with no atrophy/metaplasia by histology and pepsinogen I/II ratio > 4.0; 17H. pylori-infected subjects with atrophy/metaplasia and pepsinogen I/II ratio < 2.5; and 3 subjects with atrophy/metaplasia, no evidence of activeH. pyloriinfection, negative for anti-H. pyloriimmunoglobulin G (IgG) antibody testing, and no previous history ofH. pylorieradication. SuccessfulH. pylorieradication was achieved in 21 patients. The gastric microbiota was characterized using an Illumina MiSeq platform targeting 16S ribosomal DNA (rDNA). The mean follow-up duration was 57.4 months (range, 12–145 months), and median follow-up visit was 1 (range, 1–3). Relative abundance of Lactobacillales andStreptococcuswas increased with atrophy/metaplasia. InH. pylori-uninfected subjects (n= 8), an increase in Proteobacteria (Enhydrobacter, Comamonadaceae,Sphingobium); a decrease in Firmicutes (Streptococcus,Veillonella), Fusobacteria (Fusobacterium), Nocardioidaceae,Rothia, and Prevotella; and a decrease in microbial diversity were observed during the follow-up (ptrend < 0.05). In 10 of 21 subjects (47.6%),H. pylorieradication induced restoration of microbial diversity; however, a predominance ofAcinetobacterwith a decrease in microbial diversity occurred in 11 subjects (52.3%). The presence of atrophy/metaplasia at baseline and higher neutrophil infiltration in the corpus were associated with the restoration of gastric microbiota after successful eradication, whereas a higher relative abundance ofAcinetobacterat baseline was associated with the predominance ofAcinetobacterafterH. pylorieradication (p< 0.05). To conclude, inH. pylori-uninfected stomach, relative abundance of Proteobacteria increases, relative abundance of Firmicutes and Fusobacteria decreases, and microbial diversity decreases with aging.H. pylorieradication does not always restore gastric microbiota; in some individuals, gastric colonization byAcinetobacterspecies occurs after anti-Helicobactertreatment.