Intratumoral bacterial microbiota in gastrointestinal adenocarcinoma: From computational insights to clinical practice.

Intratumoral microbiota refers to bacteria and other organisms residing within the tumor microenvironment and are intriguingly found throughout the TME, including in cancer cells, immune cells, and stromal components. Among these microbiota, bacteria have gained attention due to their emerging roles in tumor biology. Recent research has uncovered new pathophysiological and therapeutic roles for targeting intratumoral bacterial microbiota. Emerging evidence pointed out that certain taxa, including Fusobacterium nucleatum and Porphyromonas gingivalis, can drive tumorigenic activity, whereas taxa such as Lactobacillus spp. may act as a protective agent. Overall, bacteria can influence cancer progression through mechanisms including immune modulation, metabolic reprogramming, and genomic instability. Furthermore, advances in artificial intelligence (AI) and microbiome profiling have identified prognostic microbial signatures and markers of treatment response. In addition, the mediation of the tumor microbiota via probiotics, antibiotics, engineered microbes, and fecal transplants exhibits novel approaches in targeted cancer therapy. The present review captures the role of intratumoral bacterial microbiota in adenocarcinomas and their significance in cancer development and progression as evidenced by experimental and clinical research.