Humic acids are able to form a protective film on the mucous epithelium of the gastro-intestinal tract against infections and toxins. They reduce or fully prevent the resorption of toxic metabolites after infections in case of residues of harmful substances in the body or in the case of animals, from animal feed or when switching to new feeds. Furthermore, humic acids also help to prevent excessive loss of water through the intestine. Humic acids have the ability specifically to influence microbial metabolism of proteins and carbohydrates.