Tumor Immunotherapy and Microbiome: From Bench-to-Bedside Applications.

Area of Science:

• Immunology
• Microbiology
• Oncology

Background:

• Cancer immunotherapy offers a promising alternative to conventional treatments, but challenges like drug resistance persist.
• The human microbiome's role in modulating immune responses and influencing immunotherapy efficacy is increasingly recognized.
• Mechanisms and translational potential of microbiome-based cancer therapies require further exploration.

Purpose of the Study:

• To systematically review how diverse microorganisms influence the tumor immune microenvironment.
• To elucidate the predictive value of microbial signatures for responses to immune checkpoint inhibitors (ICIs) and CAR-T cell therapy.
• To highlight emerging microbiome-based interventions for synergistic effects with immunotherapy.

Main Methods:

• Systematic review of scientific literature on microorganisms and the tumor immune microenvironment.
• Analysis of microbial modulation mechanisms, including metabolites, immune cell priming, and antigen mimicry.
• Discussion of predictive microbial signatures and interventional strategies like fecal microbiome transplantation (FMT), probiotics, and engineered bacteria.

Main Results:

• Microorganisms from various anatomical sites and intratumoral microbes modulate the tumor immune microenvironment.
• Specific microbial signatures can predict patient responses to immune checkpoint inhibitors (ICIs) and CAR-T cell therapy.
• Interventional strategies such as FMT, probiotics, and engineered bacteria show synergistic potential with immunotherapy.

Conclusions:

• Integrating mechanistic insights and translational advances provides a foundation for microbiome-based precision immunotherapy.
• Targeting the microbiome can enhance immunotherapy efficacy, improve patient survival, and reduce adverse events.
• Further research into microbiome-host interactions is crucial for developing novel cancer treatment strategies.