New insights into the effects of microbiome and its derived metabolites on targeted immunotherapy.

The significance of gut bacteria and their byproducts is gaining greater recognition, especially in the realm of immunotherapy. An imbalance in gut bacteria or their byproducts is intricately linked to the onset, progression, and treatment of cancer. Metabolites derived from gut microbiota, including short-chain fatty acids (SCFAs), secondary bile acids (SBAs), indole derivatives, and trimethylamine oxide (TMAO), engage with cellular targets to initiate intracellular signaling pathways. These signals are conveyed to the cell, influencing its growth. Targeted therapies encompass a complex and ever-evolving area that is crucial in cancer management. Nonetheless, it is vital to recognize that targeted therapy encounters a multitude of challenges. Factors influencing the success of targeted therapy include drug resistance resulting from prolonged use, side effects, and variations in genetic mutations, tumor diversity, and the complex nature of the tumor microenvironment. Recently, we have deepened our understanding of the relationship between the gut microbiome and anticancer targeted therapies. This is one face of the molecular pathologic epidemiology. This prompts us to investigate promising treatment strategies linked to these gut bacteria and their metabolites, thereby unlocking new possibilities for targeted anticancer therapies.