Food-derived peptides for senile sarcopenia: mechanisms of action, structural characteristics, and in vivo delivery challenges.

Food-derived peptides (FDPs) are attracting increasing research attention for intervention in age-related sarcopenia due to their potential muscle-protective activity. Existing studies indicate that FDPs help maintain the skeletal muscle structure and function through multiple pathways, including (1) the improvement of satellite cell differentiation disorders, (2) the synergistic regulation of protein synthesis and degradation, (3) the alleviation of oxidative stress and the improvement of mitochondrial homeostasis, (4) the modulation of inflammatory responses and immune function, and (5) the modulation of the gut-muscle axis. However, FDPs exhibit significant variability in in vivo efficacy across studies, suggesting that molecular structural characteristics and delivery mechanisms may be critical determinants of biological effects. This paper systematically reviews the relevant action mechanisms and integrates peptide sequence features, structure-activity relationships, selection of enzyme strains for raw material preparation, anti-gastrointestinal digestion and trans-biologic barrier transport properties. It focuses on the limiting factors and regulatory patterns that affect in vivo efficacy under the physiological conditions of the elderly. This work aims to provide a theoretical basis for the rational design and precise nutritional application of peptides that mitigate muscle decline.