Development of a postbiotic-based orodispersible film to prevent dysbiosis in the oral cavity

Abstract

Oral diseases affect over three billion people, being one of the most common infections worldwide. Recent studies show that to reduce the risk of caries, controlling the ecology of the oralome instead of the complete removal of both harmful and beneficial microorganisms, is more effective. This is based on the knowledge that oral diseases are not caused by a single pathogen but rather by a shift in homeostasis, called dysbiosis. Implementing strategies to prevent and control oral dysbiosis to avoid complications is of utmost importance. Conventional treatments include the use of antibiotics, which disrupt the equilibrium of the oral microbiota even further, together with the mechanical removal of the decayed area of the cavity once it is formed. Therefore, it is imperative to implement alternative strategies to overcome the disadvantages of the current conventional therapies, namely the use of broad-spectrum antibiotics. In this sense, probiotics and postbiotics have received particular attention since they can modulate the oral microbiota and decrease the dysbiotic rate in the oral cavity. However, their mechanisms of action need to be addressed to clarify and drive their possible applications as preventive strategies. In this work, Lactiplantibacillus plantarum and Lacticaseibacillus paracasei were grown in MRS broth, centrifuged, and filtered after 48h. The postbiotics were diluted to different concentrations and co-incubated with Streptococcus mutans. The antimicrobial activity was assessed. Additionally, the minimal inhibitory volume and the time needed for S. mutans inhibition were evaluated. Antibiofilm capacity was determined by the crystal violet method. Finally, an orodispersible film based on polymers and plasticizers was developed as an administration vehicle. Postbiotics demonstrated antimicrobial and antibiofilm activity against S. mutans after 24h in co-incubation. The formulation of a postbiotic-based orodispersible film based on polymers was optimized. This study offered an overview of the potential of postbiotics to prevent oral dysbiosis, focusing on their antimicrobial and anti-biofilm activity. Given the obtained results, orodispersible films impregnated with postbiotics should be considered a potential alternative to target oral dysbiosis.

Date of Award	22 Feb 2024
Original language	English
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Freni Tavaria (Supervisor)