AUTHOR=Iino Chikara , Shimoyama Tadashi , Chinda Daisuke , Arai Tetsu , Chiba Daisuke , Nakaji Shigeyuki , Fukuda Shinsaku 

TITLE=Infection of Helicobacter pylori and Atrophic Gastritis Influence Lactobacillus in Gut Microbiota in a Japanese Population

JOURNAL=Frontiers in Immunology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2018.00712

DOI=10.3389/fimmu.2018.00712

ISSN=1664-3224

ABSTRACT=<sec id="ST1"><title>Background</title><p>Suppression of gastric acid by proton pump inhibitors is associated with the increase of <italic>Lactobacillus</italic> in human gut microbiota. Gastric acid secretion is also suppressed by <italic>Helicobacter pylori</italic> infection and following atrophic gastritis. However, few studies have examined the association between <italic>H. pylori</italic> infection and <italic>Lactobacillus</italic> species in gut microbiota particularly in Japan.</p></sec><sec id="ST2"><title>Methods</title><p>A total of 1,123 adult subjects who participated in a health survey in Hirosaki City were studied. Infection of <italic>H. pylori</italic> was defined by both serum antibody and stool antigen test. The presence and the severity of atrophic gastritis were defined by the serum level of serum pepsinogens. Using 16S ribosomal RNA amplification from fecal samples, the relative abundance of <italic>Lactobacillus</italic> was calculated, and the composition ratio of each <italic>Lactobacillus species</italic> was surveyed.</p></sec><sec id="ST3"><title>Results</title><p>The relative abundance of the <italic>Lactobacillus</italic> in <italic>H. pylori</italic>-infected subjects with severe atrophic gastritis was higher comparing with those in subjects with mild atrophic gastritis and without atrophic gastritis (0.591 vs 0.068% and 0.033%, respectively; <italic>p</italic> &lt; 0.001) and also that of non-infected subjects (0.033%; <italic>p</italic> &lt; 0.001). In <italic>H. pylori</italic> non-infected subjects, both gender and age were not associated with the relative abundance of <italic>Lactobacillus</italic> in fecal samples. The proportion of <italic>Lactobacillus salivarius</italic> was high in <italic>H. pylori</italic>-infected subjects while that of <italic>Lactobacillus acidophilus</italic> was high in non-infected subjects.</p></sec><sec id="ST4"><title>Conclusion</title><p><italic>Lactobacillus</italic> in human gut microbiota could be influenced by <italic>H. pylori</italic> infection and severity of atrophic gastritis in Japanese subjects.</p></sec>