Myung-Eui Seo ¹ Byung-Joo Min ² Jung Ho Bae ^3* Ji Won Kim ^4,5* Juhan Kim ^6,7*

• ¹ Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Republic of Korea
• ² National Forensic Service Seoul Institute, Seoul, Republic of Korea
• ³ Healthcare System Gangnam Center, Seoul National University Hospital, Seoul, Republic of Korea
• ⁴ Seoul Metropolitan Government - Seoul National University Boramae Medical Center, Seoul, Republic of Korea
• ⁵ Department of Internal Medicine, College of Medicine, Seoul National University, Seoul, Republic of Korea
• ⁶ Seoul National University Biomedical Informatics (SNUBI), Seoul, Republic of Korea
• ⁷ Division of Biomedical Informatics, Seoul National University College of Medicine, Seoul, Republic of Korea

Decreasing Helicobacter pylori eradication rate is primarily attributed to antibiotic resistance, and further exacerbated by uniform drug administration disregarding host's metabolic capability. Consequently, applying personalized treatment based on antibiotic resistance associated variants and the host's metabolic phenotype can potentially increase the eradication rate. Custom next-generation sequencing panel for personalized H. pylori eradication treatment (NGS-PHET) was designed which targeting the regions for amoxicillin, clarithromycin, metronidazole, tetracycline, and levofloxacinresistance in H. pylori and human proton-pump inhibitor (PPI) metabolism. The libraries were constructed following customized methods and sequenced simultaneously. The customized framework criteria grounded in previously reported antibiotic resistance associated variants and host's PPI metabolism was applied to the NGS-PHET results and suggested a personalized treatment for each subject, which was validated through each subject's actual eradication outcome. Both previously reported and novel variants were identified from H. pylori sequencing results. Concurrently, five CYP2C19 homozygous extensive metabolizers and three CYP3A4 intermediate metabolizer were identified. Among the total of 12 subjects, clarithromycin triple therapy was suggested for five subjects, bismuth quadruple therapy was suggested for six subjects, and rifabutin triple therapy was suggested for one subject by following the customized framework criteria. The treatment suggestion for nine of the 12 subjects was consistent with the treatment that each subject achieved eradication. Applying the methodology using the NGS-PHET and customized framework helps to perform eradication treatment quickly and effectively in most patients with antibioticresistant H. pylori strains, and also useful in research to find novel antibiotic-resistance candidates.