Beyond Urease: New Potential Enzymatic Targets in Helicobacter pylori

H. pylori infection remains one of the most widespread bacterial diseases globally and a leading risk factor for peptic ulcer disease and gastric cancer. Despite decades of research, the treatment of H. pylori still depends on multidrug antibiotic regimens, whose efficacy is waning due to the rise in antimicrobial resistance. Although significant progress has been made in understanding H. pylori pathogenesis, most studies targeting bacterial enzymes have focused almost exclusively on urease, a well-characterized virulence factor, while other metabolic and structural pathways remain comparatively underexplored. Targeting essential enzymes involved in bacterial metabolism and structural integrity may disrupt vital processes, potentially reducing off-target effects on the host microbiota and overcoming resistance mechanisms. To address this gap, this systematic review, conducted according to PRISMA 2020 guidelines, synthesized experimental studies published between 2014 and 2024 that investigated enzyme-targeted compounds against H. pylori, excluding those focused on urease. Literature searches in PubMed and the Web of Science identified 49 eligible studies exploring enzymes across multiple metabolic pathways. The main pathways identified included purine metabolism, the shikimate and futalosine pathways, and nitrogen metabolism, along with several other enzymatic systems, such as thioredoxin, thymidylate, and peptidoglycan biosynthesis, all of which represent promising targets for selective inhibition in H. pylori. The reported inhibitors exhibited micromolar to submicromolar activity and, in some cases, demonstrated potent antibacterial effects with minimal cytotoxicity. However, most studies remained limited to in vitro assays, and only three included animal tests. These findings highlight enzymatic inhibition as a promising approach for the rational design of narrow-spectrum microbiome-sparing agents. Advancing these discoveries through in vivo validation and druggability assessment will be essential to translating enzyme-based inhibition into effective therapeutic options against H. pylori.