Release of bioactive peptides from whey proteins across digestion in adult humans and a static in vitro digestion model

Proteolysis of whey proteins during gastrointestinal digestion releases bioactive peptides with potential health benefits. Our study examined whey-derived peptide release after digestion under static in vitro conditions and in three adults following whey protein isolate ingestion. Using LC-MS/MS-based peptidomics, we identified 1187 unique peptides in the in vitro gastric digesta, 449 in the in vitro intestinal digesta and 1041 in the human jejunum. Among these peptides, 61 were known to exert bioactivities including ACE inhibitory, antimicrobial, DPP-IV inhibitory, antioxidant, immunomodulatory, anticancer and opioid activities. The release of antimicrobial, antioxidant and opioid peptides suggests their potential role in promoting gut health. The peptide patterns produced across digestion in the in vitro model and in adult humans were strongly similar by amino acid frequency and moderately similar in terms of peptide abundances.