Functional metabolites and inhibitory efficacy of kombucha beverage on pathogenic bacteria, free radicals and inflammation

Kombucha tea is a fermented tea that produced by acetic acid bacteria and yeast. In this study, the kombucha tea from white, green and black tea was studied for its microbial composition, chemical profile, and biological activities during 15-day fermentation period. HPLC analysis revealed key organic acids, including acetic, gluconic, and glucuronic acids in kombucha tea. In this study, white tea kombucha showed the highest glucuronic acid content. Green tea kombucha demonstrated the highest antioxidant activity by ABTS and FRAP assays. Moreover, white tea kombucha exhibited the strongest DPPH scavenging activity and high phenolic content. Additionally, kombucha tea could inhibit the growth of pathogenic bacteria, including Escherichia coli, E. coli O157:H7, Salmonella Typhi, Shigella dysenteriae, and Vibrio cholerae. Furthermore, green tea kombucha significantly inhibited nitric oxide production on LPS-stimulated RAW264.7 cells and demonstrated the strongest anti-inflammatory effect. These findings highlight a potential of kombucha tea as a functional beverage with antioxidant, antibacterial, and anti-inflammatory properties.