Study of microbial diversity in the organ after checkpoint inhibitors treatment with colitis

The intricate relationship between cancer immunotherapy, intra-tumoral microbiota, and tumor microenvironment dynamics remains poorly understood. Here, we explored intestinal bacterial translocation's role in a murine tumor immunotherapy model. We discovered that translocated enterobacteria can colonize tumors. Using dextran-tungsten trioxide nanoparticles (W@D NPs) to maintain gut mucosa, we regulated gut microbial equilibrium in immune checkpoint inhibitor (ICI) therapy. W@D NPs modulated gut microbiota, altering the intra-tumoral microbial landscape and enhancing both microbial diversity and ICI treatment efficacy. Metagenomic and transcriptomic investigations reveal that W@D NP-induced alterations in enterobacteria can transform tumor metabolism, catalyzing extracellular matrix disintegration and triggering enhanced chemokine production along with augmented lymphocyte infiltration. This revelation of how enterobacteria affect tumor microbiota presents opportunities to amplify the effects of immunotherapy. Significantly, this method has improved therapeutic outcomes in cancers typically resilient to immune-based treatments, such as pancreatic cancer, pointing to a viable tactic for reinforcing cancer immunotherapy efficacy through strategic microbial modulation.