Intracellular harboring of Helicobacter pylori within Candida species in human gastric biopsies: Evidence suggestive...

Helicobacter pylori (H. pylori) is a globally prevalent pathogen associated with gastritis, peptic ulcer and gastric adenocarcinoma. Despite available eradication therapies, treatment failures remain common, suggesting alternative survival mechanisms. Recent studies have proposed that H. pylori may persist within yeasts, particularly Candida species, through endofungal associations.

In this prospective cross-sectional study, gastric biopsy specimens from 233 patients undergoing upper gastrointestinal endoscopy at Gastroenterology Department of Ege University Hospital between July 2021 and October 2022 were analyzed. Candida spp. were isolated and examined for intracellular bacteria and intracellular H. pylori. Molecular assays, including H. pylori-specific primers and virulence gene analysis, were performed directly from total Candida DNA without prior bacterial culture. Species-level identification of Candida isolates was confirmed by PCR and sequencing.

Candida species were isolated from gastric biopsy samples of 94 (40.3%) of the total 233 patients, yielding 159 Candida isolates overall. Endofungal H. pylori was detected in 48 of these 159 isolates (30.2%), corresponding to 38 of the 94 Candida-positive patients (40.4%), as some patients yielded positive isolates from both the antrum and corpus. Region-specific analysis revealed that endofungal H. pylori-positive Candida isolates were present in 10.3% of patients from the antrum and 9.0% from the corpus. Molecular analysis further confirmed the presence of H. pylori virulence genes within yeast isolates.

Our findings suggest that Candida species may serve as an intracellular reservoir for H. pylori, potentially contributing to persistence, and may play a role in treatment failure and recurrence.