Antimicrobial peptide expression and gastric bacteria associated with
Helicobacter pylori infection in patients with gastritis
Background: The complex interplay between the continuous infection of
Helicobacter pylori (Hp) in gastric mucosa and the development of
Hp–associated gastritis remains poorly understood. The interaction
between the gastric epithelium and the immune response induced by Hp may
be an important contributing factor. Antimicrobial peptides (AMPs) can
protect the gastric mucosa from bacteria. This study aimed to
investigate the effects of Hp on the gastric flora, AMP (e.g., REG3A,
HBD2 and S100A9) expression and the mucosal ultrastructure in
Hp-positive (Hp+) patients with gastritis. Methods: The bacterial
composition was analyzed in 63 patients with gastritis using 16S rRNA
sequencing. The altered expression levels of AMPs (REG3A, HBD2 and
S100A9) were analyzed by RT-qPCR for quantification of AMP mRNA levels.
Western blotting and immunohistochemical staining were used to
investigate AMPs expressions in the gastric biopsies. Observation of the
gastric ultrastructure was performed by transmission electron microscopy
(TEM). Results: HP infection significantly reduced the abundance of
bacteria. REG3A, S100A9, and HBD2 were highly expressed in Hp+ patients.
The destruction of the epithelial cell membrane and the entry of mucus
particles into the gastric lumen were observed by TEM in Hp+ patients.
Conclusion: The findings reported here confirm the dysbiosis of gastric
microecology and AMPs expression in gastritis patients infected with Hp.
This study provides information on the complex and dynamic ecosystem and
may be helpful for further research to find a treatment alternative in
the post‐antibiotic era to eradicate multidrug‐resistant Hp strains.