FN1 and colorectal carcinoma: Advances in 16S rRNA sequencing, metagenomics, germ-free murine models, and fecal microbiota transplantation (FMT) have propelled microbiome research into a mechanistic era (10), enabling the identification of CRC-associated oncogenic taxa such as Fusobacterium nucleatum (Fn), colibactin-producing Escherichia coli (pks+ E. coli), and enterotoxigenic Bacteroides fragilis (ETBF).