Immunomodulatory peptides obtained by the enzymatic hydrolysis of whey proteins

Whey contains a number of immunomodulatory peptides that are naturally present or that are part of the primary sequence of whey proteins. These peptide sequences can be released during digestion in the gut and can also be produced by in vitro enzymatic hydrolysis. This paper reviews the existing literature on the effect of whey peptides on the specific (lymphocyte activation and proliferation, antibody production, cytokine expression) and non-specific (functions of macrophages, granulocytes and natural killer cells) immune responses. Major discrepancies in the effect of some peptides on lymphocyte proliferation have been reported while the more limited literature on antibody production is less controversial. The effects of whey peptides on hypersensitivity, induction of oral tolerance and response to infections and diseases are also reviewed. The in vitro and in vivo data on the immunomodulatory potential of whey peptides are relatively abundant. However, the potential of whey peptides as effective health ingredients remains to be demonstrated, which may be due to the lack of clinical evidence and the limitations of some in vivo models.