Antibacterial test of fermented kombucha green tea (

Acne vulgaris is a common inflammatory skin condition influenced by psychological factors and infection by Cutibacterium acnes. Long-term antibiotic use can cause resistance and disrupt the skin microbiome, creating a need for safe and effective alternatives. Green tea kombucha, a fermented product of bacteria and yeast (SCOBY), contains bioactive compounds such as polyphenols, organic acids, and probiotics with antimicrobial and anti-inflammatory properties. This study evaluated the antibacterial activity of facial cleansers formulated with green tea kombucha against Cutibacterium acnes and assessed user preferences for each formula. Antibacterial testing used the well diffusion method, supported by statistical analysis to compare the effectiveness of the formulations with a positive control. All preparations demonstrated antibacterial activity, with formula P1 producing the largest inhibition zone (28.46 ± 0.70 mm), comparable to clindamycin (31.53 ± 0.70 mm). However, formula P2 was most preferred by panelists based on texture, colour, and aroma. These findings show that green tea kombucha has strong potential as a natural active ingredient in facial cleansers to inhibit Cutibacterium acnes. Keywords: facial cleanser, natural soap, probiotic soap, kombucha, green tea, Cutibacterium acnes.