Microbial metabolites and their influence on the tumor microenvironment

Area of Science:

• Immunology
• Microbiology
• Metabolomics

Background:

• Tumor immunotherapy shows promise but faces challenges in solid tumors due to immunosuppressive environments and drug resistance.
• Metabolic reprogramming of immune cells is crucial for understanding tumor immune evasion and therapeutic resistance.
• The human commensal microbiome, acting as a 'second genome,' significantly influences host biology.

Purpose of the Study:

• To review the regulatory roles of microbial metabolites in modulating tumor immunity and immunotherapy.
• To examine the metabolic mechanisms through which microbial metabolites influence immune cell metabolism and tumor microenvironment.
• To highlight the potential of microbiota metabolism-based interventions for precision oncology.

Main Methods:

• Comprehensive literature review of studies on microbial metabolites and tumor immunometabolism.
• Analysis of mechanisms by which metabolites like SCFAs, bile acids, tryptophan metabolites, and LPS affect immune cells.
• Examination of how these metabolites reprogram immune cell metabolic pathways.

Main Results:

• Microbial metabolites act as key messengers linking the gut microbiota to tumor immunometabolism.
• Specific metabolites (SCFAs, bile acids, tryptophan metabolites, LPS) modulate tumor immunity and immunotherapy responses.
• These metabolites shape the tumor immune microenvironment and influence therapeutic efficacy by reprogramming immune cell metabolism.

Conclusions:

• Microbial metabolites play a central regulatory role in tumor immunometabolism, akin to a 'second genome.'
• Understanding these interactions provides a foundation for elucidating mechanisms of immunotherapy resistance.
• Targeting microbiota metabolism presents potential avenues for developing novel precision cancer interventions.