Oral Supplementation of Medium-Molecular-Weight Hyaluronic Acid (200–600 kDa) As a Functional Food Ingredient Alleviates <scp>D</scp>-Galactose-Induced Skin Aging

Hyaluronic acid (HA), a functional food ingredient with multitarget biological activities, shows potential in combating age-related disorders. HA levels in skin cells may serve as potential biomarkers for aging and decrease with age. This study first investigated the antiaging efficacy of oral supplementation with HA with different molecular weights (MWs) (2, 30-50, 80-100, 200-600, and 1000 kDa) in a D-galactose-induced aging mouse model. Comparative analysis revealed that 200-600 kDa HA exhibited superior performance in maintaining skin moisture, elasticity, and antifatigue properties. Concomitantly, it significantly increased the amount of HA in the tissues (serum, eyes, skin, and joints) of aging mice. And, it can significantly regulate the diversity and composition of microbial communities. Further analysis of different HA concentrations (low, medium, and high concentrations) of 200-600 kDa revealed that the medium concentration was most effective in alleviating skin aging. This study presents a novel approach to safety utilizing HA for the alleviation of skin aging.