Compared with the IL-2 group, IL-2 combining with live A. muciniphila or Amuc reduced tumor burden and prolonged survival of both murine cancer models;Compared with the IL-2 group, IL-2 combined with live A. muciniphila or Amuc increased the production of proinflammatory cytokines and the infiltration of CTLs and reduced the number of Treg lymphocytes in tumor immune microenvironment;Compared with the IL-2 group, IL-2 combined with live A. muciniphila or Amuc preserved gut barrier function and gut homeostasis. The gene discussed is IL2; the disease is cancer.