1001 Gut bacterial sphingolipid production regulates the skin microbiome, skin lipid production and skin barrier homeostasis

The stratum corneum serves as a critical barrier between the host and its external environment. Rich in ceramides, is one of largest sphingolipid reservoirs body. Our recent work using bioorthogonal labeling strategy traced sphingolipids from gut commensal Bacteroides thetaiotaomicron (BT) to liver mice fed with fat-free/high-sucrose diet demonstrated direct transfer labeled BT-sphingolipid liver. Additionally, synthesis ameliorated fatty-liver phenotype caused by high-sucrose diet. Currently, influence production on more distant sites, such skin are undefined, molecular mechanisms that mediate these interactions. Herein, we investigated impact transcriptome, concentrations, microbiota data show dysregulated lipid metabolism loss subcutaneous adipose layer induced fat-free were mitigated supplementing sphingolipid-producing B. thetaiotaomicron. regulated genes involved epidermal water balance, differentiation development tightly connected integrity function. Further, our demonstrate distinct community compared standard chow diet, expansions Staphylococcus Pseudomonas spp. addition BT-sphingolipids was able rescue phenotype. Taken together, findings importance phenotypes. also commensals metabolism, transcription, microbiota.