植物乳杆菌-SLH对实验性牙周炎的治疗效果评价OA

Objective This study aimed to investigate the therapeutic potential of clinically isolated Lactobacillus plantarum SLH in experimental periodontitis.Methods A strain of Lactobacillus plantarum SLH,isolated and purified from fecal samples of healthy infants,served as the experimental subject.Following Gram staining for morphological ob-servation,its growth curve and acid production curve were plotted.The antibacterial activity of the bacterial cells and the cell-free fermentation supernatant against Fusobacterium nucleatum and Porphyromonas gingivalis was assessed using Oxford cup agar diffusion assay.The inhibitory effect of this strain on periodontal biofilm formation was evaluated via crystal violet staining assay.Furthermore,the strain's tolerance to lysozyme and its in vitro anti-inflammatory capacity were determined.Subsequently,an experimental periodontitis model was established in rats by using ligature-induced method with 4-0 silk sutures.Twenty-four rats were randomly allocated into three groups(n=8 per group):a healthy con-trol group,a periodontitis group,and an Lactobacillus plantarum SLH treatment group.A suspension of Lactobacillus plantarum SLH was prepared in phosphate buffered saline(PBS)containing 2%sodium carboxymethyl cellulose(CMC)as a vehicle.This suspension was administered locally into the periodontal pockets at the ligation sites in the treatment group.The healthy control and periodontitis groups received local injections of an equal volume of the vehicle(2%CMC in PBS)only.This treatment regimen continued for 7 consecutive weeks.Upon completion of the administration period,clinical periodontal parameters,including the gingival sulcus bleeding index and probing pocket depth,were measured for all rats,followed by histopathological evaluation of the periodontal tissues.Results A probiotic strain was successfully isolated and purified.Following identification by 16S rDNA sequencing,it was designated as Lactobacillus plantarum SLH.Antibacterial and biofilm formation assays demonstrated that the cell-free fermentation supernatant of this strain ex-hibited significant inhibitory activity against the periodontal pathogens Porphyromonas gingivalis and Fusobacterium nu-cleatum(P＜0.05).Lysozyme tolerance test indicated that Lactobacillus plantarum SLH could withstand a relatively high concentration(3 mg/mL)of lysozyme.Furthermore,Lactobacillus plantarum SLH significantly reduced the expression levels of the inflammatory cytokines interleukin(IL)-1β,tumor necrosis factor(TNF)-α,and IL-6 in an inflammatory cell model(P＜0.000 1).In the animal experiment,compared with the control group,the periodontitis group showed signifi-cant increases in the gingival sulcus bleeding index and probing pocket depth(P＜0.000 1).Administration of Lactobacil-lus plantarum SLH resulted in a significant reduction in sulcus bleeding index(SBI)and probing depth(PD)compared with the treatment of periodontitis groups(P＜0.000 1).The body weight of the periodontitis group decreased compared with that of the controls(P＜0.05),and the Lactobacillus plantarum SLH treatment group showed a significant increase in body weight compared with the periodontitis group(P＜0.000 1).Micro-computed tomography analysis revealed pro-nounced alveolar bone resorption in the periodontitis group.This bone loss was significantly attenuated in the Lactobacil-lus plantarum SLH treatment group compared with the periodontitis group(P＜0.001).Histopathological examination us-ing hematoxylin and eosin staining showed a marked alleviation of inflammatory cell infiltration and tissue damage in the periodontal tissues of rats treated with Lactobacillus plantarum SLH.Conclusion Lactobacillus plantarum SLH exerts significant ameliorative effects on experimental periodontitis and holds potential as an adjunctive therapy for periodontal disease.