The antibacterial mechanism of the extracellular product of coagulated Heyndrickxia coagulans against Staphylococcus aureus

Heyndrickxia coagulans is a probiotic strain combining features of lactic acid bacteria and spore-forming bacilli. Its extracellular metabolites (postbiotics), such as bacteriocins, organic acids, and peptides, have attracted growing interest for skincare due to their antibacterial, anti-inflammatory, and antioxidant activities. In this study, Staphylococcus aureus was selected as a model pathogen to assess the antibacterial effects of H. coagulans metabolites using Oxford cup diffusion and minimum inhibitory concentration assays. Mechanistic investigations included bacterial growth curve analysis, membrane permeability testing, biofilm formation assessment, and evaluation of key metabolic enzyme activities. Results demonstrated that these metabolites disrupted the pathogen’s physiological functions, indicating strong antibacterial potential. This study highlights the promise of H. coagulans metabolites as safe, natural agents for skin health, providing a theoretical foundation for developing functional skincare products and strategies to prevent and control skin infections.