Akkermansia supplementation reverses the tumor-promoting effect of the fecal microbiota transplantation in ovarian cancer

Ovarian cancer (OC) remains a clinical challenge for its difficulty in early diagnosis and insensitivity to treatments. Gut microbiota modulate multiple carcinoma progression through immunoregulation. The relationship between OC and gut microbiota has not been fully characterized. We find that the feces of patients with OC demonstrate different characteristics from benign controls. After fecal microbiota transplantation (FMT) from patients with OC into OC-bearing mice, the tumor development accelerates. Further, an Akkermansia supplementation with FMT significantly suppresses OC progression in mice. RNA sequencing of tumors shows that T cell activation pathways are upregulated after Akkermansia supplementation with FMT. Moreover, acetate accumulation accompanies Akkermansia abundance elevation, which is associated with enhanced interferon γ (IFNγ) secretion of CD8+ T cells and also its tumor-killing property. This work highlights the importance of protective gut microbiome in immune surveillance of OC, which connects accumulation of acetate and the cytotoxic function of CD8+ T cells by increasing IFNγ secretion. [Display omitted] •FMT from patients with OC promotes tumor development in OC-bearing mice•Akkermansia supplementation suppresses tumor progression in OC FMT mice•Akkermansia supplementation enhances the anti-tumor immune function in OC FMT mice•Gut homeostasis connects with CD8+ T cell activation in OC-immune microenvironment Wang et al. perform fecal microbiota transplantation (FMT) from patients with ovarian cancer (OC) into OC-bearing mice and find that Akkermansia supplementation could enhance gut homeostasis, improve the immune microenvironment, and suppress OC progression.