The Potential Teeth Bleaching and Halitosis Prevention Effects of Pediococcus inopinatus THK-30, a Kimchi-Derived Lactic Acid Bacterium: In Vitro Study

Abstract

Background: Recent developments in addressing dental aesthetic concerns, encompassing issues like teeth discoloration and halitosis, underscore the demand for safer alternative solutions. Purpose: This study aims to confirm the effects of lactic acid bacteria (LAB) from kimchi on artificial teeth bleaching and their potential impact in terms of preventing halitosis-related bacteria. Materials and Methods: To evaluate the antimicrobial effects against oral pathogens, disc diffusion tests and broth microdilution methods were used. Additionally, crystal violet analysis was performed to confirm the biofilm inhibition effect. The bleaching effects on stained artificial teeth were analyzed using the CIEDE2000 colorimetric method. Statistical analyses were performed using GraphPad Prism 9 with one-way and two-way ANOVA, with the significance level set at α < 0.05. Results: The strain THK-30, isolated from kimchi, exhibited antibacterial activity against Streptococcus mutans, Porphyromonas gingivalis, and Fusobacterium nucleatum, and was identified as Pediococcus inopinatus. Moreover, THK-30 showed a synergistic antibacterial effect against Gram-negative oral pathogens with 8% sodium hexametaphosphate (SHMP). In the stained artificial teeth bleaching test and artificial teeth biofilm inhibition test, the cell-free supernatant of THK-30 displayed significant teeth bleaching effects and caused the inhibition of biofilm formation, both independently and in combination with SHMP 8%. Conclusions: This study has demonstrated the potential applicability of LAB in teeth discoloration and halitosis. These findings are poised to provide a foundation for the development of research pertaining to the control of oral bacteria.