Background: Since “Helicobacter pylori (H. pylori) infection” was set as the indication in the Japanese Society for Helicobacter Research (JSHR) Guidelines 2009, eradication treatment for H. pylori gastritis is covered under insurance since 2013 in Japan, and the number of H. pylori eradication has rapidly increased. Under such circumstances, JSHR has made the third revision to the “Guidelines for diagnosis and treatment of H. pylori infection” for the first time in 7 years.Methods: The Guideline Committee held 10 meetings. Articles published between the establishment of the 2009 Guidelines and March 2016 were reviewed and classified according to the evidence level; the statements were revised on the basis of this review. After inviting public comments, the revised statements were finalized using the Delphi method.Results: There was no change in the basic policy that H. pylori infectious disease is an indication for eradication. Other diseases presumed to be associated with H. pylori infection were added as indications. Serum pepsinogen level, endoscopic examination, and X‐ray examination were added to the diagnostic methods. The effects of 1‐week triple therapy consisting of potassium‐competitive acid blocker (P‐CAB), amoxicillin, and clarithromycin have improved, and high eradication rates can also be expected with proton pump inhibitors (PPI) or P‐CAB combined with amoxicillin and metronidazole. If the susceptibility test is not performed, the triple PPI or P‐CAB/amoxicillin/metronidazole therapy should be chosen, because the PPI/amoxicillin/metronidazole combination demonstrated a significantly higher eradication rate than PPI/amoxicillin/clarithromycin. In the proposal for gastric cancer prevention, we divided gastric cancer prevention measures by age from adolescent to elderly, who are at an increased gastric cancer risk, and presented measures for gastric cancer prevention primarily based on H. pylori eradication.Conclusion: We expect the revised guidelines to facilitate appropriate interventions for patients with H. pylori infection and accomplish its eradication and prevention of gastric cancer.

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 β‐diversity of gut microbiota were assessed.Results: Supplementation with BFR prevented the decrease in a‐diversity after eradication therapy (Day 7). β‐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.