Даваа–Баасан 08:30–20:00 · Бямба 09:00–16:00
library@mnums.edu.mn
/

Renchinsengee, Namsrai

Loading...
Thumbnail Image
Товч нэр
Renchinsengee, Namsrai
Бүтэн нэр
Renchinsengee Namsrai
Латин нэр
Renchinsengee Namsrai
Албан тушаал
Судлаач
Харьяалал
ORCID

Settings

Now showing 1 - 2 of 2
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Species-level dynamics of gastric microbiome after Helicobacter pylori eradication in high-risk Mongolian population
    (2026-02)
    Renchinsengee, Namsrai
    ;
    Batsaikhan, Saruuljavkhlan
    ;
    Khangai, Ayush
    ;
    Boldbaatar, Gantuya
    ;
    Luvsandagva, Bayasgalan
    BACKGROUND: Species-level resolution is essential to understand gastric microbiome recovery after Helicobacter pylori eradication, yet short-read 16 S rRNA approaches often obscure clinically relevant changes. METHODS: Gastric biopsies from 121 adults in Bayan-Ölgii, Mongolia (71 H. pylori-positive, 50 H. pylori-negative) were analyzed, including nine paired pre- and post-eradication gastric biopsy samples collected six months apart, enabling exploratory longitudinal analysis. Full-length 16 S rRNA (V1-V9) sequencing was performed using the Oxford Nanopore platform with EMU taxonomic assignment (SILVA v138.1/NCBI RefSeq). Ecological changes were evaluated using diversity indices, principal coordinates analysis (PCoA) with PERMANOVA, and differential abundance testing (DESeq2, FDR < 0.05). Eradication therapy (esomeprazole-bismuth-doxycycline-levofloxacin) achieved success in 54 of 57 H. pylori-positive patients (94.7%). RESULTS: H. pylori-positive microbiomes were dominated by H. pylori (91.8% ± 3.9%) and exhibited markedly reduced diversity (Shannon = 0.44 ± 0.11) compared with H. pylori-negative samples (2.08 ± 0.25; p < 0.001). Six months after eradication, diversity increased significantly (2.17 ± 0.20; p = 0.0001), with enrichment of oral commensals including Streptococcus mitis (↑ 11.9×), Neisseria elongata (↑ 13.7×), and Prevotella melaninogenica (↑ 13.0×). However, post-eradication profiles at six months remained distinct from H. pylori-negative communities (PERMANOVA R² = 0.12; p = 0.02). In total, 174 amplicon sequence variants changed significantly, including persistence of Fusobacterium nucleatum. CONCLUSIONS: Nanopore full-length 16 S sequencing reveals fine-scale, clinically relevant shifts that are masked by partial-gene assays. Eradication rapidly restores microbial diversity, but at six months, is associated with a novel ecological equilibrium rather than complete normalization. This species-resolved approach offers a practical framework for post-eradication microbiome monitoring and may inform strategies to reduce residual gastric cancer risk in high-burden populations.
    Scopus© Citations 1
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Study of Helicobacter pylori Isolated from a High-Gastric-Cancer-Risk Population: Unveiling the Comprehensive Analysis of Virulence-Associated Genes including Secretion Systems, and Genome-Wide Association Study
    (MDPI AG, 2023-09)
    Saruuljavkhlan, Batsaikhan
    ;
    Alfaray, Ricky Indra
    ;
    Oyuntsetseg, Khasag
    ;
    Gantuya, Boldbaatar
    ;
    Khangai, Ayush
    BACKGROUND: The prevalence of gastric cancer in Mongolia, in East Asia, remains the highest in the world. However, most Helicobacter pylori strains in Mongolia have a less virulent Western-type CagA. We aimed to determine how H. pylori genomic variation affected gastric diseases, especially gastric cancer, based on comprehensive genome analysis. METHODS: We identified a set of 274 virulence-associated genes in H. pylori, including virulence factor and outer membrane protein (OMP) genes, the type four secretion system gene cluster, and 13 well-known virulence gene genotypes in 223 H. pylori strains and their associations with gastric cancer and other gastric diseases. We conducted a genome-wide association study on 158 H. pylori strains (15 gastric cancer and 143 non-gastric cancer strains). RESULTS: Out of 274 genes, we found 13 genes were variable depending on disease outcome, especially iron regulating OMP genes. H. pylori strains from Mongolia were divided into two main subgroups: subgroup (Sg1) with high risk and Sg2 with low risk for gastric cancer. The general characteristics of Sg1 strains are that they possess more virulence genotype genes. We found nine non-synonymous single nucleotide polymorphisms in seven genes that are linked with gastric cancer strains. CONCLUSIONS: Highly virulent H. pylori strains may adapt through host-influenced genomic variations, potentially impacting gastric carcinogenesis.
    Scopus© Citations 10