KRAS and colorectal carcinoma: Although the number of CRC patients with KRAS mutations was not the highest (18/39, Table 2), they carried the most kinds of specific OTUs relative to patients with other mutations and had obviously a higher abundance of Faecalibacterium, Roseburia, Megamonas, Lachnoclostridium, and Harryflintia and a lower abundance of Bifidobacterium at the genus level compared to patients without KRAS mutations (Fig. 5a).