Microbiome and metabolome analyses reveal novel interactions between the skin microflora and skin metabolites in atopic dermatitis

Atopic dermatitis (AD) is one of the most common inflammatory skin diseases. Skin microecological imbalance is an important factor in the pathogenesis of AD, but the specific mechanism of its interaction with humans is not completely clear.In this study, 16S rRNA sequencing was conducted to reveal the skin microbiome of AD patients. Changes in skin metabolites were detected by LC-MS metabolomics. We then explored the potential mechanism of interaction by analyzing the correlation between skin bacterial communities and metabolites in corresponding skin samples. After quality control, samples from 18 AD patients and 18 healthy volunteers were successfully subjected to 16S sequencing and LC-MS metabolomic detection. AD patients had dysbiosis of the skin microbiome with decreased species richness and evenness. The relative abundance of Staphylococcus increased significantly, while the abundances of Propionibacterium, Brevundimonas, Lactobacillus and Lysobacter decreased significantly. The relative abundances of Staphylococcus, Acinetobacter, Lactobacillus and Streptococcus in healthy females were significantly higher than those in healthy males. Multiple metabolites of purine metabolism and phenylalanine metabolism pathways (such as xanthosine/xanthine and L-phenylalanine/trans-cinnamate) were increased in AD patients. Spearman correlation analysis revealed that Staphylococcus was strongly positively correlated with various compounds in phenylalanine metabolism and purine metabolic pathways. Brevundimonas and Lactobacillus were negatively correlated with various compounds related to purine metabolism, phenylalanine metabolism and sphingolipid signaling pathways.