Table 1.

Regulation of intestinal microbiota in cancer immunotherapy

Microbiota (or products)	Immune regulation	Impact on cancer immunotherapy
Bifidobacteria	Promoting maturation of DCs Activating lymphocytes Upregulating IFN-γ and increasing pro-inflammatory cytokine Initiating the proliferation of tumor-specific CD8+ T cells	Enhancing PD-1 blockade
B. fragilis	Activating Th1 cells Promoting Tregs proliferation Promoting maturation of DCs	Enhancing CTLA-4 blockade
A. muciniphila	Increasing CXCR3+CCR9+CD4+ T cells	Enhancing PD-1 blockade
Escherichia Clostridium	Inducing the differentiation of Tregs and inhibiting inflammation	Enhancing CTLA-4 blockade
Faecalibacterium	Promoting the proliferation of CD4+ or CD8+ T cells Promoting the production of Tregs and upregulating the expression of ICOS	Enhancing PD-1 blockade Enhancing CTLA-4 blockade
Bacteroides	Upregulating the system’s MDSC and Tregs Causing a systemic inflammatory response through the TLR-NF inflammatory pathway	Impeding PD-1 blockade Impeding CTLA-4 blockade
microbial-derived SCFAs	Promoting the differentiation of Tregs	Enhancing CTLA-4 blockade