Stability and Anti-inflammatory Properties of A Probiotic Toothpaste

Objectives: Anti-inflammatory immunomodulation during episodes of gingivitis may be one of the key benefits of probiotic application in the oral cavity. The design of the formulation is a prerequisite for conserving the efficacy of the active agent. Here we show that water-free toothpaste (WFTP) essentially extends stability of probiotics compared to standard formulations (STP) and preserves their anti-inflammatory effects.
Methods: The toothpaste was formulated by dispersing hydroxypropyl-cellulose on the surface of 1,3-Butandiol and mixing with a STEPHAN-universal-machine. Silica, foaming agent and different salts were sequentially added and mixed. Finally probiotic bacteria were added as lyophilized powder in a concentration of 1% and dispersed in a mixer.
Bacterial numbers were determined in technical triplicates by spread plate assay (anaerobic incubation on MRS-agar at 37°C for 48-72h) for stability testing during 12 months.
For screening the anti-inflammatory response, viable bacteria were extracted from freshly prepared base by differential centrifugation. Anti-inflammatory properties of the probiotic bacteria were analyzed in an ex-vivo model system using LPS-stimulated (Salmonella enterica serotype typhimurium SL1181,10 ng/ml) primary human monocytes. The release of MCP-1 (monocyte chemoattractant protein), interleukin (IL)-6, IL-8, tumor necrosis factor alpha (TNF-α), prostaglandin E₂ (PGE₂) and 8-isoprostane was analyzed using ELISA/EIA techniques. Experiments were repeated (n=4) with 2 independently treated supernatants per buffy coat.
Results: Water exclusion from toothpastes distinctly prolongs probiotic stability compared to standard toothpaste base (ΔViability_STP [CFU/g] = log₁₀5/ 1 week vs. ΔViability_WFTP[CFU/g]= log₁₀1/ 24 weeks). Thus viable probiotics, extracted from the toothpaste base, mediated robustly a dose-dependent, anti-inflammatory effect in LPS-stimulated human primary monocytes without affecting cell viability.
Conclusions: In conclusion our data suggest that probiotics can be stably formulated in a water-free toothpaste and have the potential to dampen early inflictions of mild gingivitis by application through a commonly accepted format.