Effects of potential probiotics on the expression of cytokines and human β-defensins in human gingival epithelial cells and in vivo efficacy in a dog model.

OBJECTIVES: The aims of this study were to examine the effects of probiotic strains on the expression of cytokines and human β-defensins-2-4 in human gingival epithelial cells and to investigate the in vivo efficacy of probiotics in a dog model.

DESIGN: Selected probiotics, Lacticaseibacillus paracasei SD1, L. rhamnosus SD4, L. rhamnosus SD11 and Limosilactobacillus fermentum SD7, were examined for the expression of human β-defensins-2-4, and cytokine responses after stimulated by various periodontopathogens. Subsequently, an in vivo study was set as a randomized, double-blind, placebo-controlled intervention in a dog model. A total of 20 dogs with mild gingivitis were randomly assigned to either the probiotic or control group. The effects of probiotics on periodontopathogenic- and cytokine levels were analyzed after 4 weeks of intervention.

RESULTS: It showed that all probiotics could induce human β-defensins-2-4, interleukin-1β, interleukin-6, interleukin-8, and tumor necrosis factor-α expressions in human gingival epithelial cells; however, a significant difference had been found among the strains. When individual probiotic strain was combined to periodontopathogens, a significant reduction of IL-8 expression was found. Results of the in vivo study demonstrated that the bacterial levels, especially Porphyromonas gingivalis, and the interleukin-8 levels were significantly decreased after receiving the probiotic products compared to the controls.

CONCLUSION: The results of the in vitro and in vivo studies in dogs are encouraging to support the effectiveness of a mixture of probiotic treatments for improvement of periodontal health by reducing periodontopathogens and interleukin-8 levels. Therefore, such probiotics preparation could possibly have therapeutic potential in human periodontitis.