Sir,

In their article entitled Metformin abrogates Fusobacterium nucleatum-induced chemoresistance in colorectal cancer by inhibiting miR-361-5p/sonic hedgehog signaling-regulated stemness (British Journal of Cancer volume 128, pages 363–374 (2023), https://doi.org/10.1038/s41416-022-02044-6) [1], Hong et al. describe an interesting molecular circuitry whereby infection by the tumor-associated pathobiont F. nucleatum would contribute to Colorectal cancer (CRC) chemoresistance via a novel pathway involving MYC, miR-361-5p and the embryonic, stemness-related signaling cascade initiated by Sonic Hedgehog. One of the most relevant findings of this article is that Metformin specifically abolishes the effect of Fn on cancer cell stemness and chemoresistance by upregulating the miRna above, suggesting a possible repurposing of this antidiabetic drug in association with chemotherapy in CRC with high Fn load.