The Anti-Biofilm Properties of Phloretin and Its Analogs against and Its Complex Flora.

is crucial for the pathogenesis of periodontitis. This research investigated the effects of the fruit-derived flavonoid phloretin and its analogs on the growth of pure and the flora of mixed with the symbiotic oral pathogens and . The results showed that the tested flavonoids had little effect on the biofilm amount of pure , but significantly reduced the biofilm amount of mixed flora to 83.6~89.1%. Biofilm viability decreased to 86.7~92.8% in both the pure- and mixed-bacterial groups after naringenin and phloretin treatments. SEM showed that phloretin and phlorizin displayed a similar and remarkable destructive effect on and the mixed biofilms. Transcriptome analysis confirmed that biofilm formation was inhibited by these flavonoids, and phloretin significantly regulated the transcription of quorum sensing. Phlorizin and phloretin reduced AI-2 activity to 45.9% and 55.4%, respectively, independent of the regulation of related gene transcription. This research marks the first finding that these flavonoids possess anti-biofilm properties against and its intricate bacterial community, and the observed performance variations, driven by structural differences, underscore the existence of intriguing structure-activity relationships.