Indirect mechanisms of colonization resistance include microbiome-mediated regulation of the integrity of the gut barrier function to prevent penetration/ translocation of potential pathogens.9 Mucins are glycoproteins which act to protect the gut barrier against inflammation and colitis.10 Pathogens such as Clostridioides difficile are recognized to decrease the level of the major intestinal mucin, muc2;11 conversely, the commensal bacterial species, Bifidobacterium longum, restores growth of mucin.12 This evidence concerns the gene MUC5AC and colitis.