Abstract
The bidirectional communication network known as the gut-skin axis suggests that gastrointestinal equilibrium significantly influences cutaneous physiology and barrier integrity. This 12-week, randomized, double-blind, controlled clinical trial evaluated the efficacy of a personalized nutrition intervention guided by baseline gut microbiome profiling on facial skin hydration and transepidermal water loss (TEWL) in healthy young adults. Sixty participants (aged 20–35 years) were randomized into either a personalized nutrition group (PNG, n = 30), receiving targeted dietary prescriptions designed to optimize microbial diversity and short-chain fatty acid (SCFA) production, or a general healthy diet control group (CG, n = 30). Cutaneous biophysical parameters were measured at baseline, week 6, and week 12 under standardized environmental conditions using a Corneometer CM 825 and Tewameter TM 300. Stool samples were analyzed via 16S rRNA amplicon sequencing. At week 12, the PNG demonstrated a statistically significant increase in stratum corneum hydration (+24.3% vs. +7.1% in CG; p < 0.001) and a pronounced reduction in TEWL (-19.8% vs. -4.6% in CG; p < 0.001). Taxonomic shifts characterized by increased relative abundance of Faecalibacterium prausnitzii and Akkermansia muciniphila were strongly correlated with enhanced epidermal barrier markers. These findings substantiate that precision nutritional regimens modulating the gut microbiome can substantially elevate skin hydration and barrier performance, underscoring the therapeutic and aesthetic potential of microbiome-targeted nutricosmetics.
