Probiotic Response in Periodontal Disease

Probiotics are live microorganisms that can be taken as supplements and have shown promise in playing a beneficial role in improving clinical conditions that are characterized by chronic inflammation, such as periodontal disease (PD). The human gut microbiome is composed of trillions of bacteria that reside throughout the gastrointestinal tract and has an important role in the modulation of inflammatory responses in the human host. There is evidence that PD is associated with alterations in the oral and gut microbiomes, suggesting that probiotics may reduce inflammation through microbiome modulation. However, individual responses to probiotics can be highly variable, and robust predictors of probiotic responsiveness remain poorly defined. There is also limited knowledge about how the oral and gut microbiome interact even though there is growing evidence for a bidirectional oral-gut axis with implications for host immunity, inflammation, and probiotic responsiveness. The overarching goal of this project is to identify oral and gut microbiome features that predict responsiveness to probiotic interventions as an adjuvant treatment for PD. We will conduct a double-blind randomized controlled trial in which New Hampshire adults with stage III PD will be randomized to receive a 12-week adjuvant intervention of either a daily probiotic (n=45) or placebo (n=45) lozenge. The probiotic intervention will consist of a once daily lozenge containing a standard dose of 200 million CFU of two strains of Limosilactobacillus reuteri (DSM 17938 and ATCC PTA 5289), a commercial formulation demonstrated to be safe and well-tolerated in this population over this treatment length. The primary outcome to quantify responsiveness to the probiotic as an adjuvant therapeutic for PD will be within-subject change from baseline in inflammatory markers, and oral and gut microbiome composition.