The Role of Gut Microbiota in Colorectal Cancer Pathogenesis: A Comprehensive Literature Review

Colorectal cancer (CRC) represents a significant global health burden, ranking as the third most frequently diagnosed malignancy worldwide. Emerging evidence has established a compelling association between gut microbiota dysbiosis and CRC pathogenesis, revealing complex mechanisms through which specific bacterial communities modulate carcinogenesis. This comprehensive review synthesizes current knowledge on the mechanistic contributions of gut microbiota to CRC development, with particular emphasis on key pathogenic bacteria including <i>Fusobacterium nucleatum</i>, <i>Bacteroides fragilis</i>, and <i>Escherichia coli</i>. We examine the molecular pathways through which these microorganisms promote tumorigenesis, including chronic inflammation induction, immune response modulation, metabolic reprogramming, and direct genotoxic effects. Furthermore, we discuss the therapeutic implications of microbiota-targeted interventions and the potential utility of microbial biomarkers for early CRC detection. Understanding the intricate host-microbiota interactions in CRC pathogenesis may facilitate the development of novel preventive strategies and therapeutic approaches for this devastating disease.