Bacterial composite vaccine improves tumor immune microenvironment and inhibits tumor growth by reshaping mouse gut microbiota and bile acid metabolism

In conclusion, our study suggests that BCV can up-regulate the abundance of L. reuteri to improve the intestinal microenvironment. L. reuteri enhances the effector functions of CD4+ and CD8+ T cells by down-regulating the level of TCA, and finally play an anti-tumor role. Therefore, BCV could be of great value in tumor therapy.