Soy fermentation by orally isolated putative probiotic Streptococcus salivarius for healthy oral

Aim: Consumption of aglycones-rich fermented soy has been positively associated with the recuperation of systemic inflammation. As oral conditions have an impact on overall health and diseases, the reestablishment of bacteria particularly by indigenous oral probiotic is believed to be able to reverse oral inflammation by antagonize oral pathogen and thus maintaining good oral health. Streptococcus salivarius can be combined with bioactive isoflavone aglycones to further improve oral healthiness. This study aimed to explore decent advantages by indigenous source of Streptococcus isolated from healthy periodontal to ferment soy while maintaining probiotic properties before delivering in product targeting oral health. Materials and Methods: Putative probiotic properties of isolated strains were explored through antibiotic susceptibility ensuring safe strain consumption. S. salivarius from Taylor's University Culture Collection (TUCC) 1254 was selected for probiotic properties evaluation, in comparison with the type strain. Both strains were evaluated for fermentation ability in soy through growth, β-glucosidase assay, and isoflavone bioconversion. Results: The antagonistic ability of S. salivarius TUCC 1254 was better under anaerobic than microaerobic condition; the strain also showed higher colonizing ability to epithelial tissue than the tooth surface resemblance. The strain showed vast cell growth accompanied by organic acid production and higher β-glucosidase enzyme to bioconvert isoflavone glucosides to bioactive aglycones that could reduce oral inflammation than K12. Soy improved auto-aggregation ability of S. salivarius, which could promote biofilm formation and thus could achieve enhanced oral pathogen-eradicating intention. Conclusion: This study suggested that indigenous bacteria could serve as a better source of oral probiotics and coupling with fermented soy bioactive isoflavone aglycones, become a deliverable platform for improving oral health.