Antibacterial and Antibiofilm Potentials of LAB-Derived Metabolites Against Porphyromonas gingivalis

Introduction: Porphyromonas gingivalis is a primary pathogen implicated in the onset and progression of periodontal disease, primarily due to its ability to form resilient biofilms and express virulence factors that disrupt host immune responses. Conventional treatments, such as mechanical debridement and chemical antimicrobials, often face limitations including resistance development and cytotoxicity. Lactic acid bacteria (LAB) are known to produce bioactive metabolites with antimicrobial and anti-inflammatory properties, offering a promising alternative for oral health applications. This study aims to evaluate the inhibitory and antibiofilm activities of LAB-derived metabolites against P. gingivalis. Methods: Selected LAB strains (Lactiplantibacillus rhamnosus SUK1 and Lactiplantibacillus plantarum T2), isolated from human milk and tempeh, were cultured anaerobically in MRS broth at 37°C for 48 hours. The resulting supernatants were centrifuged, filtered, and treated with NaOH, catalase, and proteinase K to obtain treated cell-free supernatants (TCFS). These were subsequently lyophilized to produce L-TCFS. Antibacterial efficacy was assessed using broth microdilution assays, while antibiofilm activity was evaluated using crystal violet staining. Results: All TCFS and L-TCFS samples demonstrated significant inhibitory effects against P. gingivalis. Among them, L-TCFS from a mixture strain S2 at a concentration of 50 mg/ml exhibited the highest antibacterial activity, achieving an 80.15% reduction in bacterial growth. This sample outperformed individual strain treatments including T2 and SUK1. Additionally, L-TCFS samples effectively reduced biofilm formation, although 0.12% chlorhexidine remained the most potent agent in comparison. Conclusion: LAB-derived metabolites, particularly L-TCFS from the mixture strain S2, exhibit strong antibacterial and antibiofilm activity against P. gingivalis. These findings suggest their potential as safer alternatives or adjunct therapies in the management of periodontal disease, contributing to the development of microbiome-friendly oral care solutions.