Bifidobacterium animalis subsp. lactis BL-G101 Protects Against UVB-Induced Photoaging in HS68 Dermal Fibroblasts

Background: Skin photoaging is primarily caused by prolonged ultraviolet (UV) exposure, which manifests as dryness and wrinkle formation. Recent studies highlight that beneficial microorganisms have garnered considerable attention for their emerging role in modulating host health, especially in skin photoaging. Methods: To investigate the role of two strains, Bifidobacterium animalis subsp. lactis BL-G101 (BL-G101) and Lactobacillus acidophilus LA-G80 (LA-G80), in UVB-induced photoaging, we conducted experiments on human Hs68 dermal fibroblasts. Using untargeted metabolomics, we explored the potential mechanisms underlying BL-G101 treatment in Hs68 cells by profiling differential metabolites in the intracellular and extracellular metabolomes. Results: Our results demonstrated that BL-G101 significantly inhibited UVB-induced reduction in collagen and hyaluronic acid (HA), whereas LA-G80 showed no notable effects. BL-G101 treatment also protects against UVB-induced oxidative stress, which was evidenced by significantly decreased MDA levels and enhanced SOD activity. Moreover, BL-G101 suppressed UVB-induced inflammation by significantly decreasing IL-1β and TNF-α levels. SA-β-gal staining revealed a reduction in senescent fibroblasts following BL-G101 treatment. Untargeted metabolomics suggested that the anti-photoaging effects of BL-G101 may involve the modulation of metabolic pathways of biosynthesis of cofactors, glycine, serine and threonine metabolism, and arginine biosynthesis. Conclusions: These preclinical findings demonstrate that BL-G101 reduces dermal photoaging, supporting its potential as a functional food ingredient against skin aging.