The growth of fecal zonulin and i-FABP demonstrates a certain relationship between the severity of clinical manifestations and the increase in the values of non-invasive markers of small intestinal damage, also they can serve as markers of permeability and damage of intestinal barrier in CD, which will open up new possibilities for understanding the processes of restoration of the small intestinal mucosa to improve the prognosis (outcome) of the disease. This evidence concerns the gene FABP2 and Cowden disease.