Health issues of whey proteins: 3. Gut health promotion

This paper reviews the potential of whey protein to promote gut health. The high digestibility and specific amino acid composition of whey protei, as present in whey powder, whey protein concentrate and whey protein isolate, explain why ingestion of whey protein will exert this beneficial effect. The high true digestibility will reduce the flow of nitrogen from the ileum into the colon and limit the formation by the intestinal flora of nitrogenous compounds that are toxic to the colonic epithelial cells. Whey protein is an excellent source of threonine, S-containing- and branched-chain- essential amino acids (BCAA). Threonine is largely and directly incorporated into intestinal mucins, which protect the intestinal cells and strengthen the barrier junction of the gut. Sulfur-containing amino acids serve as precursors of the anti-oxidant compounds glutathione and taurine, which display anti-inflammatory properties. This is important in the prevention and/or reduction of inflammatory bowel disease. Glutamine in whey and glutamine derived from the precursor BCAA serve as substrate for immune competent cells, which are largely present in the gut-associated lymphoid tissue. Other issues relating whey protein to gut health are antimicrobial and anti-viral proteins in whey and piptides with anti-microbial activity that are formed during whey protein digestion