A rat model of necrotizing enterocolitis was treated with HMOs, which directly induced the expression of protein disulfide isomerase (PDI), increased the level of intestinal mucin Muc2, decreased the permeability of the intestine to macromolecular dextran, and reduced bacterial adhesion (Wu et al., 2019). The gene discussed is P4HB; the disease is necrotizing enterocolitis.