Bioactive peptides from casein and whey proteins

Casein and whey proteins are rich sources of bioactive peptides with the potential to positively influence human health. These peptides are released by proteolytic digestion of the native protein molecule and many have demonstrated a capacity to influence the immune response through both direct and indirect means. Immunomodulatory peptides have the potential to interact directly with specific components of the innate and acquired immune systems, eliciting a series of downstream responses. On the other hand, antibacterial, bifidogenic and mucin-stimulating peptides have the potential to indirectly influence immune responses by modulating gut microbial composition and improving gut homeostasis. Peptide release can be achieved in vitro using commercial proteases or by employing proteolytic bacteria, while bioactive peptides may also be released in vivo during gastrointestinal digestion. Considering that milk is the sole food of newborn mammals, the presence of biologically active peptides in the gut undoubtedly influences immune development, a critical element of host health.