CEACAM5 and colorectal carcinoma: These results suggested that CEA, CA19-9, and these key fecal microbes including Peptostreptococcus, Parvimonas, Shewanella, Oscillibacter, Eggerthella, Gemella, Fenollaria, Staphylococcus, Ezakiella, Finegoldia, and Neisseria may be co-biomarkers for the disease occurrence, development, and non-invasive diagnosis of CRC.