The effect of Lactobacillus rhamnosus administration against Porphyromonas gingivalis in vivo

Background: Periodontitis is a chronic inflammatory disease initiated by polymicrobial infection, characterized by an imbalance between subgingival microbiota and host immune defense. This imbalance results in the destruction of tooth-supporting tissues, with Porphyromonas gingivalis identified as a key pathogen. Conventional periodontal therapies may not fully control destructive inflammation, highlighting the need for effective adjunctive strategies. Objective: To evaluate the impact of the probiotic Lactobacillus rhamnosus on inflammatory responses and wound healing processes in an in vivo periodontitis model. Methods: Gingival tissue samples from a P. gingivalis-induced periodontitis model were analyzed to determine the effects of L. rhamnosus supplementation on the levels of pro- and anti-inflammatory mediators and wound healing markers. Results: In a rat model of periodontitis, probiotic supplementation suppressed inflammation by reducing TNF-α, IL-6, and IL-1β levels while increasing IL-10 expression in the gingival epithelium, thereby restoring the balance between pro- and anti-inflammatory mediators. Additionally, treatment accelerated wound healing, as indicated by upregulation of TGF-β1 and downregulation of MMP-8. Conclusion: Our study shows that L. rhamnosus attenuates periodontitis primarily by modulating the host inflammatory response through downregulation of pro-inflammatory cytokines. These findings highlight its potential as an immunomodulatory probiotic and support future clinical trials as an adjunct to conventional periodontal therapy.