Mining Oral Probiotics Based on Their Pathogen Inhibition and Deodorization Roles

ABSTRACT With the increasing demands of oral health, this in vitro study proposed a high‐throughput strategy for the screening of oral probiotic strains based on the inhibition zones against the main oral pathogens Fusobacterium nucleatum and Porphyromonas gingivalis , as well as the elimination of H 2 S and NH 3 . Four highly active strains, Streptococcus salivarius MY‐6, Pediococcus pentosaceus ZY‐1, Lactiplantibacillus plantarum X7022, and Limosilactobacillus fermentum S1L18, were identified from 41 candidate strains. All four strains were able to survive in saliva and tolerate both α‐amylase and lysozyme. Moreover, they showed significant effects in inhibiting pathogen growth and biofilm formation, and in disrupting pathogen cell morphology, with MY‐6 exhibiting the strongest overall activity. These strains also coaggregated with the pathogens and downregulated virulence‐related gene expression, which may further contribute to their antagonistic effects. Finally, their deodorizing activities were evaluated by GC‐MS and an electronic nose, and MY‐6 again showed the most prominent performance. Taken together, these in vitro findings indicate that S. salivarius MY‐6 is a promising oral probiotic candidate for the control of oral pathogens and halitosis.