More and more studies have shown that gut microbiota have notable impact on cancer therapy. Therapies such as chemo-therapeutic drugs and immune checkpoint inhibitors can affect the integrity of the intestinal barrier and influence the microbe-host interaction. Gut microbiota interacting with the matrix, nerve, endocrine, immune cells in the intestinal tract can have systemic effects on hosts, and ultimately affect the host's immune response, making gut microbiota essential for anti-tumor efficacy studies. Using severely immunodeficient germ-free NCG mouse models, we established a triple humanized mouse models which have human tumor cells, human immune checkpoint components, and human gut microbiota, allowing for evaluation of the impact of gut microbiota on the anti-tumor efficacy of anti-tumor drugs.