Abstract
The connection between microbial infections and tumor formation is notably exemplified by Helicobacter pylori (H. pylori) and its association with gastric cancer (GC) and colorectal cancer (CRC). While early studies hinted at a link between H. pylori and colorectal neoplasms, comprehensive retrospective cohort studies were lacking. Recent research indicates that individuals treated for H. pylori infection experience a significant reduction in both CRC incidence and mortality, suggesting a potential role of this infection in malignancy development. Globally, H. pylori prevalence varies, with higher rates in developing countries (80-90%) compared to developed nations (20-50%). This infection is linked to chronic gastritis, peptic ulcers, and GC, highlighting the importance of understanding its epidemiology for public health interventions. H. pylori significantly increases the risk of non-cardia GC. Some meta-analyses have shown a 1.49-fold increased risk for colorectal adenomas and a 1.70-fold increase for CRC in infected individuals. Additionally, H. pylori eradication may lower the CRC risk, although the relationship is still being debated. Although eradication therapy shows promise in reducing GC incidence, concerns about antibiotic resistance pose treatment challenges. The role of H. pylori in colorectal tumors remains contentious, with some studies indicating an increased risk of colorectal adenoma, while others find minimal association. Future research should investigate the causal mechanisms between H. pylori infection and colorectal neoplasia, including factors like diabetes, to better understand its role in tumor formation and support widespread eradication efforts to prevent both gastric and colorectal cancers.