Food–Medicine Homologous Qiongyu Gao Attenuates Skin Photoaging by Remodeling Gut Microbiota and Restoring Mitochondrial Energy Metabolism

Bioactive food ingredients that regulate the gut microbiota are promising dietary strategies for supporting systemic health, but their roles in skin photoaging remain insufficiently defined. Qiongyu Gao (QYG), a classical food–medicine homologous formula composed of Rehmanniae Radix, Panax ginseng, and Poria cocos, was evaluated as an oral functional food candidate for UV-induced skin photoaging. QYG was chemically characterized by HPLC and UPLC–QTOF–MS/MS. Young and aged mice were subjected to D-galactose plus UVA/UVB exposure and orally administered QYG, followed by skin transcriptomics, gut microbiota sequencing, serum metabolomics, and validation in UVB-injured primary dermal fibroblasts. QYG alleviated wrinkle formation, epidermal thickening, oxidative stress, inflammation, extracellular matrix degradation, collagen disorganization, and hyaluronic acid loss. Multi-omics analysis showed that QYG selectively remodeled gut microbiota, enriching Lactobacillus-, Bifidobacterium-, and Akkermansia-associated taxa, regulated serum metabolites related to energy and lipid metabolism, and enriched mitochondrial energy metabolism-related pathways in photoaged skin. In fibroblasts, QYG-containing serum restored mitochondrial membrane potential, reduced ROS accumulation and cellular senescence, and regulated AMPK/PGC-1α-associated markers. These findings support QYG as a promising food–medicine homologous functional food candidate for skin health maintenance through gut microbiota-associated systemic metabolic regulation.