Patients infected with H. pylori undergo the gastroscopy. During the gastroscopy, gastric mucus samples are collected, from which DNA is extracted. The DNA samples are subjected the full-auto SNP analyzer and the from A to G mutation of 23s rRNA of H. pylori at the positions of 2142 and 2143 is measured. When the mutation is detected, patients are diagnosed to be infected with clarithromycin-resistant strains of H. pylori and therefore, treated with the triple therapy with vonoprazan 20 mg bid + amoxicillin 750 mg bid + metronidazole 250 mg bid for 1 week. When the mutation is not detected, patients are considered to be infected with clarithromycin-sensitive strains of H. pylori and therefore, treated with the triple therapy with vonoprazan 20 mg bid + amoxicillin 750 mg bid + clarithromycin 200 mg bid for 1 week. The success or failure of eradication was determined based on the 13C-urea breath test performed 1 month after the therapy. The total eradication rates with this strategy was compared with that by the standard regimen in Japan performed in the same period of the study.
Patients infected with H. pylori are treated with the individualized regimen which is based on the mutation of 23S rRNA of H. pylori.