Marine‐Derived Collagen Peptides as Emerging Biofactors: Molecular Characteristics, Biological Mechanisms, and Potential Roles in Healthy Aging

Marine-derived collagen (MDC) represents a sustainable source of bioactive biomolecules derived from marine processing by-products, with emerging applications in molecular nutrition and healthy aging. Compared with mammalian collagen, MDC exhibits distinctive structural characteristics, including variable imino acid composition, reduced thermal stability, and enhanced enzymatic accessibility, which determine its physicochemical properties, processing behavior, and biological potential. These structural features also underpin the distinct functional roles of native collagen and collagen-derived peptides: intact MDC retains triple-helical architectures and extracellular matrix-interactive motifs that support cellular responses and tissue homeostasis, whereas hydrolyzed marine collagen peptides (MCPs) are orally administered bioactive peptides that can undergo gastrointestinal absorption and have been investigated for potential systemic health effects. This review summarizes current advances in the molecular characteristics, sustainable production, structural modification, and biological functions of MDC and MCPs, emphasizing the structure-function relationships that govern their nutritional and physiological effects. We discuss how extraction and processing strategies regulate collagen architecture, peptide generation, and bioactivity, and further examine the molecular mechanisms that have been proposed to underlie the antioxidant, anti-inflammatory, metabolic regulatory, and musculoskeletal protective effects of MCPs. Particular attention is given to aging-associated physiological decline, in which oxidative stress, chronic inflammation, and extracellular matrix deterioration contribute to impaired tissue homeostasis. Emerging experimental evidence suggests that marine collagen-derived bioactive peptides may modulate key signaling pathways, including Nrf2-mediated antioxidant responses, NF-κB-related inflammatory regulation, and pathways involved in connective tissue remodeling and metabolic balance. Finally, we highlight current challenges limiting the broader application of MDC-derived biofactors, including source variability, structural and compositional standardization, bioavailability characterization, and the need for well-designed human studies. By integrating marine sustainability, molecular structure, and biological function, MDC and its derived peptides may serve as promising food-derived biofactors with potential applications in supporting healthy aging and age-related health maintenance.