Dietary supplementation with Dendrobium officinale flowers alleviates chronic UVB exposure-induced skin photoaging in hairless mice

• Dietary Dendrobium officinale flowers (DOF) attenuated UVB-induced wrinkle formation and skin dryness and suppressed related gene expression. • DOF inhibited UVB-induced epidermal thickness increase and collagen loss. • DOF reduced the expression of senescence marker p21 and DNA damage marker p53 and inhibited apoptosis in the skin of photoaged mice. • DOF modified skin gene expression profiles and key pathways associated with skin photoaging. • DOF mitigated gut microbiota dysbiosis in photoaged mice by modulating diversity, composition, function, and co-occurrence networks. Chronic ultraviolet exposure, a significant global public health concern, contributes to skin photoaging, characterized by diminished skin function and compromised defensive capabilities, thereby posing risks to overall health. Dendrobium officinale flowers (DOF), known for their diverse physiological activities including antioxidant, antidepressant, hepatoprotective, and lifespan-extending properties, were investigated for their potential to counteract ultraviolet B-induced skin photoaging in vivo in the present study. Dietary DOF supplementation significantly improved skin hydration, reduced wrinkles, prevented epidermal thickening, increased collagen density, and suppressed aging marker, DNA damage, and apoptosis in photoaged mice. Transcriptomic analysis revealed that DOF modifies skin gene expression profiles and multiple key pathways essential for skin health. Furthermore, 16S rRNA sequencing demonstrated that DOF effectively alleviates gut microbiota dysbiosis induced by chronic ultraviolet B exposure. Correlation analysis further identified strong associations between gut microbiota composition, skin photoaging parameters, and hub genes within key signaling pathways. These findings collectively underscore the potential of DOF as a promising therapeutic strategy for preventing UVB-induced skin photoaging, offering novel insights into combating extrinsic skin aging. Dietary supplementation with Dendrobium officinale flowers ameliorates chronic UVB-induced skin photoaging and gut microbiota dysbiosis in mice