Antibiofilm Activity of Psidium guajava Leaf Polyphenols Against Oral Pathogens

Abstract

Background: A plant-derived antibiofilm fraction may complement conventional plaque-control agents while limiting broad microbial suppression. Objective: To evaluate polyphenol-rich Psidium guajava leaf fraction in comparison with vehicle control and chlorhexidine reference using a in-vitro biofilm experiment. Methods: The draft protocol included 30 experimental units or participants involving single- and dual-species oral biofilms of Streptococcus mutans and Candida albicans. The intervention was administered or tested for 48 hours. The primary outcome was biofilm biomass reduction, with additional assessment of minimum biofilm inhibitory concentration, viable count, extracellular polysaccharide content, surface coverage by confocal microscopy. Standardized laboratory, clinical, or food-analysis procedures were applied, and between-condition effects were evaluated with two-sided tests at α=0.05. Results: The Psidium guajava fraction reduced dual-species biofilm biomass in a concentration-dependent manner to 31 ± 5% of control at 100 µg/mL (p<0.001).
At 100 µg/mL, extracellular polysaccharide content declined to 37 ± 6% of control and viable S. mutans counts decreased by 2.7 log10 CFU, with substantial thinning of the confocal biofilm architecture. Direction and magnitude of the findings of the dummy were internally consistent across the primary and secondary endpoints, and tolerability or assay quality was acceptable. Conclusions: The example data indicate that the polyphenol-rich fraction of the Psidium guajava leaf might be used to efficiently reduce the biomass of the biofilm by inhibiting glucosyltransferase activity, decreasing microbial adhesion, and interfering with formation of extracellular polymeric matrix. The findings herein are based on a complete manuscript-development example and should be replaced with ethically obtained and independently verified observations before submitting to scientific publications. Keywords: Psidium guajava; oral biofilm; Streptococcus mutans; polyphenols; antimicrobial.