Stevioside reduces inflammation in periodontitis by changing the oral bacterial composition and inhibiting P. gingivalis

Background: Nowadays, excessive sugar intake is an issue for many people, and the use of sugar substitutes is becoming popular. Stevioside is considered to be a promising non-calorie sweetener with anti-inflammatory effects. However, the effects and mechanisms of it in the oral environment and periodontitis remain unclear. Therefore, we aims to explore the effect of stevioside on periodontitis in mice.Methods: The periodontitis model was established in mice treated with 0.1% stevioside, 10% glucose, or water. Micro-CT scanning was used to assess alveolar bone resorption, RT-PCR was used to evaluate the inflammatory factors expression and Porphyromonas gingivalis(P. gingivalis) invasion in the gingiva. The composition of the oral bacteria was analysed using 16S rRNA sequence in the saliva. In addition, P. gingivalis was co-cultured with stevioside in different concentrations in vitro, and bacterial activity was detected from optical density values and live/dead staining. The virulence was detected using RT-PCR, and biofilm formation was detected using scanning electron microscopy.Results: Compared with 10% glucose, the intake of 0.1% stevioside could reduce alveolar bone absorption and osteoclasts while also decreasing IL-6, TNF-a, IL-1b, and P. gingivalis in the gingiva of periodontitis mice. Moreover, the composition of the oral bacteria in the group treated with stevioside was more similar to that of the controls. In addition, in vitro stevioside reduced the bacterial activity and toxicity of P. gingivalis in a dose-dependent manner and affected its biofilm composition.Conclusion: Our research shows that compared with 10% glucose, 0.1% stevioside intake can reduce alveolar bone resorption and inflammation in periodontal tissues, and its effect on bacterial composition was making it similar to that of a healthy environment. In vitro, high concentrations of stevioside reduced P. gingivalis activity, biofilm formation, and virulence expression. Therefore, stevioside has the potential to be a beneficial alternative to glucose for patients with periodontitis.