Prevalence of non- <i>Helicobacter pylori Helicobacter</i> (NHPH) species in <i>H. pylori</i> -associated gastritis

<i>Helicobacter pylori</i> is a well-established cause of gastritis and gastric malignancy, but other <i>Helicobacter</i> species-collectively termed non-<i>Helicobacter pylori Helicobacter</i> (NHPH)-also contribute to gastric disease. This study retrospectively analysed the prevalence of NHPH in 1115 routine gastric biopsies from a large academic medical centre submitted for <i>H. pylori</i> drug susceptibility genotyping using a next-generation sequencing (NGS) assay targeting <i>16S</i> and <i>23S</i> rRNA genes. NGS results of identified pathogens were compared against those identified on histology. NHPH species were detected in 15 of 1115 cases (1.3%), including 7 NHPH-only infections and 8 mixed infections with <i>H. pylori</i> Detected NHPH species included <i>Helicobacter heilmannii</i>, <i>Helicobacter felis</i> and <i>Helicobacter bizzozeronii</i> No mutations associated with antimicrobial resistance were identified in NHPH. Broader molecular testing may improve recognition of mixed infections and guide more accurate diagnosis and treatment for gastric disease.