Vol. 6, Issue 1, Part A (2024)

The widespread use of antibiotics has transformed human health but also profoundly disrupted the commensal microbiota, leading to antibiotic resistance and altered host-microbe interactions. Emerging evidence links antibiotic-induced dysbiosis to an increased risk of several cancers, including colorectal, breast, liver, and gastric malignancies. Antibiotic exposure promotes the selection and horizontal transfer of resistance genes within gut microbial communities, fostering the persistence of pro-inflammatory, genotoxic, and metabolically dysregulated bacterial populations. These changes can compromise mucosal immunity, alter bile acid metabolism, increase reactive oxygen species production, and facilitate tumor-promoting signaling. Furthermore, resistant bacteria within the tumor microenvironment may reduce therapeutic efficacy and contribute to immunotherapy resistance. This review highlights recent findings on how antibiotic-driven microbiome remodeling and resistance gene dissemination contribute to carcinogenesis, emphasizing the need for microbiota-preserving antimicrobial strategies in oncology.