The prebiotic effects of fructooligosaccharides enhance the growth characteristics of Staphylococcus epidermidis and enhance the inhibition of Staphylococcus aureus biofilm formation

Oligosaccharides have been shown to enhance the production of short chain fatty acids (SCFAs) by gut probiotics and regulate gut microbiota, to improve intestinal health. Recent research indicates that oligosaccharides may also positively impact skin microbiota by selectively promoting the growth of skin commensal bacteria and inhibiting pathogenic bacteria. However, the specific metabolic and regulatory mechanisms of skin commensal bacteria in response to oligosaccharides remain unclear. This study aims to explore the influence of four oligosaccharides on the growth and metabolism of Staphylococcus epidermidis and further identify skin prebiotics that can enhance its probiotic effects on the skin. Fructooligosaccharides (FOS), isomaltooligosaccharide (IMO), galactooligosaccharides (GOS) and inulin were compared in terms of their impact on cell proliferation, SCFAs production of S. epidermidis CCSM0287 and the biofilm inhibition effect of their fermentation supernatants on Staphylococcus aureus CCSM0424. Furthermore, the effect of FOS on S. epidermidis CCSM0287 was analysed by the transcriptome analysis. All four oligosaccharides effectively promoted the growth of S. epidermidis CCSM0287 cells, increased the production of SCFAs, with FOS demonstrating the most significant effect. Analysis of the SCFAs indicated that S. epidermidis CCSM0287 predominantly employs oligosaccharides to produce acetic acid and isovaleric acid, differing from the SCFAs produced by gut microbiota. Among the four oligosaccharides, the addition of 2% FOS fermentation supernatant significantly inhibited S. aureus CCSM0424 biofilm formation. Furthermore, RNA sequencing revealed 162 differentially expressed genes (84 upregulated and 78 downregulated) of S. epidermidis CCSM0287 upon FOS treatment compared with glucose treatment. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis highlighted differences in the amino acid synthesis pathway, particularly in terms of arginine biosynthesis. FOS promotes cell proliferation, increases the SCFA production of S. epidermidis CCSM0287 and enhance the inhibition of S. aureus biofilm formation, suggesting that FOS serves as a potential prebiotic for strain S. epidermidis CCSM0287.