Modulation of gut microbiota to overcome resistance to immune checkpoint blockade in cancer immunotherapy.

Immune checkpoint blockade therapies that target CTLA-4 and PD-1/PD-L1 have ushered in a new era of cancer treatment. Nevertheless, a significant proportion of patients demonstrated primary or acquired resistance. Harnessing gut microbiota has been an emerging novel therapeutic strategy to overcome resistance. Here we summarized the current research status of gut microbiota in immune checkpoint blockade therapies, clinical trials, underlying mechanisms and challenges of microbiome research in checkpoint immunotherapy. Findings from preclinical models, standardized microbiome analysis and progress of multi-omic approaches may better disclose the interaction between gut microbiota and immune checkpoint inhibitors (ICIs) and traditional Chinese medicine can be a potential microbiome modulator to sensitize the response to ICIs.