AUTHOR=Shin Cheol Min , Kim Nayoung , Park Ji Hyun , Lee Dong Ho 

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

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.621879

DOI=10.3389/fmicb.2020.621879

ISSN=1664-302X

ABSTRACT=<p><italic>Helicobacter pylori</italic> infection changes gastric microbiota profiles. However, it is not clear whether <italic>H. pylori</italic> eradication 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 following <italic>H. pylori</italic> eradication. Changes in corpus mucosa-associated microbiota were evaluated in 43 individuals with endoscopic follow-up &gt; 1 year, including 8 <italic>H. pylori</italic>-uninfected and 15 <italic>H. pylori</italic>-infected subjects with no atrophy/metaplasia by histology and pepsinogen I/II ratio &gt; 4.0; 17 <italic>H. pylori</italic>-infected subjects with atrophy/metaplasia and pepsinogen I/II ratio &lt; 2.5; and 3 subjects with atrophy/metaplasia, no evidence of active <italic>H. pylori</italic> infection, negative for anti-<italic>H. pylori</italic> immunoglobulin G (IgG) antibody testing, and no previous history of <italic>H. pylori</italic> eradication. Successful <italic>H. pylori</italic> eradication 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 and <italic>Streptococcus</italic> was increased with atrophy/metaplasia. In <italic>H. pylori</italic>-uninfected subjects (<italic>n</italic> = 8), an increase in Proteobacteria (<italic>Enhydrobacter</italic>, Comamonadaceae, <italic>Sphingobium</italic>); a decrease in Firmicutes (<italic>Streptococcus</italic>, <italic>Veillonella</italic>), Fusobacteria (<italic>Fusobacterium</italic>), Nocardioidaceae, <italic>Rothia</italic>, and Prevotella; and a decrease in microbial diversity were observed during the follow-up (<italic>p</italic> trend &lt; 0.05). In 10 of 21 subjects (47.6%), <italic>H. pylori</italic> eradication induced restoration of microbial diversity; however, a predominance of <italic>Acinetobacter</italic> with 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 of <italic>Acinetobacter</italic> at baseline was associated with the predominance of <italic>Acinetobacter</italic> after <italic>H. pylori</italic> eradication (<italic>p</italic> &lt; 0.05). To conclude, in <italic>H. pylori-</italic>uninfected stomach, relative abundance of Proteobacteria increases, relative abundance of Firmicutes and Fusobacteria decreases, and microbial diversity decreases with aging. <italic>H. pylori</italic> eradication does not always restore gastric microbiota; in some individuals, gastric colonization by <italic>Acinetobacter</italic> species occurs after anti-<italic>Helicobacter</italic> treatment.</p>