Microbiota and esophageal cancer: From dysbiosis to carcinogenesis.

Esophageal cancer remains a significant global health challenge, ranking as the seventh most common cancer and the sixth leading cause of cancer-related mortality worldwide. Emerging evidence highlights the critical role of microbiota dysbiosis, an imbalance in microbial communities, in the development of esophageal carcinogenesis. This review summarizes current research on alterations in the esophageal, oral, and gut microbiota associated with esophageal cancer, with a focus on esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC). Distinct microbial signatures have been observed, such as increased Fusobacterium and decreased Streptococcus in ESCC, an abundance of lactic acid-producing bacteria in EAC, and characteristic shifts in oral and gut microbial profiles in patients. We also explore the mechanisms linking dysbiosis to carcinogenesis, including chronic inflammation driven by bacterial lipopolysaccharides (LPS), the production of carcinogenic metabolites (e.g., acetaldehyde and hydrogen sulfide), and the disruption of the epithelial barrier by bacterial adhesins. These findings underscore the microbiota's potential as a diagnostic biomarker and therapeutic target while emphasizing the need for further research to clarify causal relationships and to translate these insights into clinical strategies for esophageal cancer prevention and management.