Lectin is the name for a type of protein that is concentrated more in some foods than others. Foods with the highest lectin activity include: grains (especially wheat), legumes (especially soy), some nuts, dairy, and nightshades (e.g. eggplant, tomatoes, potatoes, peppers, etc.). The frequent consumption of large amounts of lectins has been shown potentially to damage the lining of the digestive system. An article published in April of 2017 suggests that lectins can cause disease. Some lectins can actually move through the intestinal wall and even deposit themselves in distant organs. If you are interested more information can be found at this link.