Gastric cancer remains a significant global health challenge, causing a substantial number of cancer-related deaths, particularly in China. While the exact causes of gastric cancer are still being investigated, () infection has been identified as the primary risk factor, which triggers chronic inflammation and a multistage progression of gastric lesions that may lead to carcinogenesis over a long latency time. Since the 1990s, numerous efforts have focused on assessing the effectiveness of eradication in preventing new cases of gastric cancer among both the general population and patients who have undergone early-stage cancer treatment. This body of work, including several community-based interventions and meta-analyses, has shown a reduction in both the incidence of and mortality from gastric cancer following treatment, alongside a decreased risk of metachronous gastric cancer. In this review, we seek to consolidate current knowledge on the effects of treatment on gastric cancer prevention, its systemic consequences, cost-effectiveness, and the influence of antibiotic resistance and host characteristics on treatment outcomes. We further discuss the potential for precision primary prevention of treatment and comment on the efficient implementation of test-and-treat policies and allocation of health resources towards minimizing the burden of gastric cancer globally.