MALDI-TOF MS and 16S RNA Identification of Culturable Gastric Microbiota: Variability Associated with the Presence of <i>Helicobacter pylori</i>

• Main Authors: Claudia Troncoso, Monica Pavez, Alvaro Cerda, Marcelo Oporto, Daniel Villarroel, Edmundo Hofmann, Eddy Rios, Armando Sierralta, Luis Copelli, Leticia Barrientos
• Format: Article
• Language: English
• Published: MDPI AG 2020-11-01
• Series: Microorganisms
• Subjects: <i>Helicobacter pylori</i>; gastric lesion; microaerophilic bacteria; gastric microbiota
• Online Access: https://www.mdpi.com/2076-2607/8/11/1763

<i>Helicobacter pylori</i> is the main bacteria associated with gastroduodenal diseases. Recent studies have reported that gastric microbiota might be modified by the <i>H. pylori</i> colonization, favoring gastric lesions′ development. In Chile, the region of La Araucanía concentrates a high risk of gastric cancer associated with <i>Helicobacter pylori</i> colonization, rurality, poverty, and Mapuche ethnicity. Hence, we aimed to identify the culturable gastric microbiota and characterize its variability at different stages of epithelial injury, based on its <i>H. pylori</i> colonization in dyspeptic patients from this Chilean region. Microaerophilic bacteria strains were isolated from antrum biopsies of 155 dyspeptic patients′ biopsies and identified using MALDI-TOF MS or <i>16sRNA</i> gene sequencing for non-pylori species identification, and <i>UreC</i> gene amplification for <i>H. pylori</i> confirmation. We found 48 species from 18 families, mainly belonging to <i>Neisseriaceae</i> (21.3%), <i>Streptococcaceae</i> (20.0%), <i>Actynomicetaceae</i> (9.0%), <i>Enterobacteriaceae</i>, and <i>Lactobacillaceae</i> (4.5%); however, <i>Streptococcaceae</i> and <i>Actinomycetaceae</i> families showed a significant reduction in samples infected with <i>H. pylori</i>, along with a considerably lower diversity of species. Our results revealed a microbiota modification due to <i>H. pylori</i> colonization associated with the gastric epithelial state, suggesting a potential microbiota role for developing and progressing gastric diseases.