Effect of probiotics during vonoprazan-containing triple therapy on gut microbiota in Helicobacter pylori infection: A randomized controlled trial.

BACKGROUND: Probiotics are beneficial to patients with Helicobacter pylori infections by modulating the gut microbiota. Biofermin-R (BFR) is a multiple antibiotic-resistant lactic acid bacteria preparation of Enterococcus faecium 129 BIO 3B-R and is effective in normalizing the gut microbiota when used in combination with antibiotics. This study aimed to determine the effect of BFR in combination with vonoprazan (VPZ)-based therapy on gut microbiota. METHODS: Patients with positive urinary anti-H pylori antibody test (primary test) and fecal H pylori antigen test (secondary test) were examined. Patients in group 1 (BFR- ) received VPZ (20 mg twice daily), amoxicillin (750 mg twice daily), and clarithromycin (400 mg twice daily) for 7 days. Patients in group 2 (BFR+ ) received BFR (3 tablets/day) for 7 days, in addition to the aforementioned treatments. Following treatment, the relative abundance, α-diversity, and ß-diversity of gut microbiota were assessed. RESULTS: Supplementation with BFR prevented the decrease in a-diversity after eradication therapy (Day 7). ß-diversity was similar between groups. The incidence rate of diarrhea was non-significantly higher in the BFR- than in the BFR+ group (73.1% vs 56.5%; P = .361). Stool consistency was comparable in the BFR+ group on Days 7 and 1 (3.86 ± 0.95 vs 3.86 ± 1.46; P = .415). CONCLUSION: Biofermin-R combined with VPZ-based therapy resulted in higher microbial α-strain diversity and suppressed stool softening during H pylori eradication therapy.

Usefulness of detection of clarithromycin-resistant Helicobacter pylori from fecal specimens for young adults treated with eradication therapy.

BACKGROUND: To prevent Helicobacter pylori infection in the younger generation, it is necessary to investigate the prevalence of antibiotic-resistant H. pylori. OBJECTIVE: The aim of this study was to evaluate the method of PCR-based sequencing to detect clarithromycin (CAM) resistance-associated mutations using fecal samples as a noninvasive method. METHODS: DNA extracted from fecal specimens and isolates from gastric biopsy specimens were collected from patients with H. pylori infection. Antibiotic resistance to CAM was analyzed by molecular and culture methods. The detection rates of CAM resistance-associated mutations (A2142C or A2143G) were compared before and after eradication therapy. RESULTS: With CAM resistance of H. pylori evaluated by antibiotic susceptibility test as a gold standard, the sensitivity and the specificity of gene mutation detection from fecal DNA were 80% and 84.8%, respectively. In contrast, using DNA of isolated strains, the sensitivity and the specificity were 80% and 100%. Of the seven cases in which eradication was unsuccessful by triple therapy including CAM, CAM-resistant H. pylori, and resistance-associated mutations were detected in three cases, CAM-resistant H. pylori without the mutation was detected in two patients, and resistance-associated mutation was only detected in one patient. CONCLUSION: PCR-based sequencing to detect CAM resistance-associated mutations using isolates or fecal samples was useful for finding antibiotic-resistant H. pylori infection. Although the specificity of the detection from fecal samples compared with antibiotic susceptibility testing was lower than that from isolates, this fecal detection method is suitable especially for asymptomatic subjects including children. Further improvement is needed before clinical application.

Modified allele-specific primer-polymerase chain reaction method for analysis of susceptibility of Helicobacter pylori strains to clarithromycin.

BACKGROUND AND AIM: Most clarithromycin-resistant strains of Helicobacter pylori have a mutation from adenine (A) to guanine (G) at position 2142 or 2143 of the 23S rRNA gene. Our aim in this study was to develop a polymerase chain reaction (PCR)-based assay that could determine these mutations in a single reaction tube. METHODS: We designed the forward primer FP2143G and the reverse primer RP2142G, which specifically anneal with the 2143G- and 2142G-mutated sequences, respectively, of the 23S rRNA gene of H. pylori. We also designed the forward primer FP-1 and reverse primer RP-1 upstream and downstream from the positions 2142 and 2143, respectively, to distinguish the wild-type A2142G and A2143G mutations from each other by amplicon sizes. DNA was extracted from 292 gastric tissue samples positive for rapid urease test, and the DNA underwent the PCR reaction. The results were compared with minimum inhibitory concentrations (MIC) for clarithromycin. RESULTS: Helicobacter pylori strains with A2142G, A2143G and wild type could be distinguished by amplicon sizes by a single PCR reaction. The genotyping results were correlated well with the MIC values for clarithromycin. The median MIC for clarithromycin of the wild-type strains was <0.015 microg/mL. Those of strains with 2142G or 2143G were > or =1.0 microg/mL. CONCLUSION: Our new PCR-based assay for 23S rRNA mutations of H. pylori is a useful method for detecting clarithromycin-resistant strains of H. pylori easily.