Oral probiotic development

Oral diseases such as dental caries, periodontitis and halitosis are developed by a shift in the composition and function of the microbiota that inhabits the corresponding niche (supragingival plaque, subgingival plaque and dorsum of the tongue, respectively), in which an overgrowth of potentially pathogenic microorganisms occurs, generating a dysbiosis. In healthy conditions there is a balance between the beneficial microbiota and the so-called pathobionts. Therefore, therapeutic and preventive strategies should be aimed at restoring the healthy microbial ecosystem and we believe that probiotics can provide a powerful strategy to restore the balance in the oral cavity. Contrary to the traditional application of probiotics derived from dairy products or from the gut, our laboratory is investigating bacteria that naturally inhabit the mouth, in order to maximize their colonization and function. Along this line, oral probiotics can provide several beneficial actions, including: i) displace potentially pathogenic microorganisms by inhibiting their growth or competing for the niche; ii) produce substances that enhance or promote physiological conditions for oral health and growth of healthy microorganisms; iii) modulating the immune system towards an anti-inflammatory response. In our group, we have developed an oral probiotic with this triple action against dental caries, the new species Streptococcus dentisani, for which different clinical trials have been completed. In addition, we have identified several oral isolates with the ability to reduce nitrate and nitrite producing beneficial metabolites for oral and systemic health. These potential probiotics against periodontitis and halitosis are currently in the phase of clinical trials in humans.

Agar plate with a loan culture of the caries pathogen Streptococcus mutans where 4 colonies of our probiotic Streptococcus dentisani  produce inhibition rings due to the action of bacteriocins.

Participants: PhD. Bob T. Rosier and Dr. María D. Ferrer García

Selected publications:

• Rosier B.T., Palazón C., García-Esteban S., Artacho A., Galiana A., Mira A. (2021) A single dose of nitrate increases resilience against acidification derived from sugar fermentation by the oral microbiome. Front. Cell. Infect. Microbiol. 11: 692883
• Ferrer, M. D., López-López, A., Nicolescu, T., Perez-Vilaplana, S., Boix-Amorós, A., Dzidic, M., Garcia S., Artacho A., Llena C., Mira, A. (2020). Topic application of the probiotic Streptococcus dentisani improves clinical and microbiological parameters associated with oral health. Frontiers in cellular and infection microbiology, 10, 465.
• López-López, A., Camelo-Castillo, A., Ferrer, M. D., Simon-Soro, Á., & Mira, A. (2017). Health-associated niche inhabitants as oral probiotics: the case of Streptococcus dentisani. Frontiers in microbiology, 8, 379.