Bioactive Peptides from Dairy Products: A Systematic Review of Advances, Mechanisms, Benefits, and Functional Potential

Bioactive peptides (BAPs) from dairy products have garnered increasing attention as natural agents with health-promoting properties, including antihypertensive, antioxidant, antimicrobial, immunomodulatory, opioid, and antidiabetic activities. This systematic review synthesizes research published between 2014 and 2024, retrieved from Scopus and PubMed, and selected according to PRISMA guidelines. A total of 192 studies met the inclusion criteria, collectively reporting over 3200 distinct peptides, with antihypertensive sequences, predominantly angiotensin-converting enzyme (ACE) inhibitors, constituting the largest category (n = 1237). β-casein was the principal precursor across bioactivities, followed by αs1-casein, β-lactoglobulin, and α-lactalbumin. Peptides were primarily produced via enzymatic hydrolysis, microbial fermentation, and gastrointestinal digestion, with peptide profiles influenced by the type of milk, microbial strains, and processing conditions. While cow’s milk remained the dominant source, investigations into goat, sheep, camel, buffalo, and donkey milk revealed species-specific biopeptides. Recent advances in proteomics have enhanced peptide identification and bioactivity prediction, enabling the discovery of novel sequences. These findings underscore the significant potential of dairy-derived BAPs as functional food components and nutraceutical ingredients, while highlighting the need for further in vivo validation, bioavailability studies, and broader exploration of underrepresented milk sources.