Lactic acid bacteria have functions in immunoregulation, antagonism, and pathogen inhibition. The purpose of this study was to evaluate the effectiveness of lactic acid bacteria (LAB) in countering oral pathogens and develop related products. After a series of assays to 450 LAB strains, 8 heat-inactivated strains showed a strong inhibitory effect on a caries pathogen, Streptococcus mutans, and 308 heat-inactivated LAB strains showed a strong inhibitory effect on a periodontal pathogen, Porphyromonas gingivalis. The key reasons for inhibiting oral pathogens were bacteriocins produced by LAB and the coaggregation effect of the inactivated cells. We selected Lacticaseibacillus (Lb) paracasei 111 and Lb.paracasei 141, which had the strongest inhibitory effects on the above pathogens, was the main oral health food source. The optimal cultural conditions of Lb. paracasei 111 and Lb. paracasei 141 were studied. An oral tablet with a shelf life of 446 days made of the above strains was developed. A 40 volunteers' clinical study (CSMUH IRB number: CS05065) was conducted with this tablet in the Periodontological Department of the Stomatology Research Center, Affiliated Hospital of Chung Shan Medical University (Taiwan). After 8 weeks of testing, 95% and 78.9% of patients showed an effect on reducing periodontal pathogens and improving probing pocket depth, respectively, in the oral tablet group.
Keywords: Lacticaseibacillusparacasei; Porphyromonas gingivalis; Streptococcus mutans; caries; lactic acid bacteria (LAB); oral pathogen; periodontal disease.