A specific strain of naturally occurring oral lactobacilli was isolated and identified based on morphological, biochemical, and 16S rRNA gene sequencing. The phylogenetic affiliation of the isolate confirmed that the NK02 strain had close association with the Lactobacillus salivarius. An effective mouthwash was developed for treatment of periodontitis and suppression of the indicator bacterium Aggregatibacter actinomycetemcomitans which is an obvious pathogen of periodontal disease. The mouthwash containing L. salivarius NK02 was tested at a dose level of 10 (colony forming units (CFU) ml), monitoring over a period of 4 weeks. The study was a randomized double-blind placebo control trial, and the patients were treated in two groups of control and test by using scaling and root planing (SRP) + placebo and scaling and root planing (SRP) + probiotic, respectively. It appeared that the probiotic mouthwash was able to inhibit the bacterial growth on both saliva and sub-gingival crevice and exhibited antibacterial activity against A. actinomycetemcomitans. The results also showed that SRP+ probiotic treatment led to a significant decrease of gingival index (GI) and bleeding on probing (BOP) compared with that of SRP + placebo for the probiotic group. The rate of decrease in pocket depth was displayed in the group with SRP + probiotic treatment equal to 1/2 mm, and probing pocket depth (PPD) value was decreased in the probiotic bacteria treatment group that can explain the decrease in inflammation in gingiva. Our findings suggest that probiotic mouthwash is healthy for daily use as an alternative for maintaining dental and periodontal health.

Background The etiology of gingival overgrowth due to cyclosporine A (CsA) is still unknown. The aim of this study was to determine the possible role of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) on extra-cellular matrix (ECM) homeostasis when treated with different levels of CsA and its difference between fetal and adult human gingival fibroblasts (HGFs). Methods Each group of cells (adult and fetal) was cultured in 40 wells that consisted of four different CsA treatment concentrations. Every 10 wells were treated with 0, 50, 100, and 150 ng/mL of CsA which makes a total of 80 wells. Supernatants of every well were used to determine the concentration of MMPs and TIMPs using the Elisa kits from Boster, CA, USA. Results MMP-1 level increased with the treatment of CsA when treated with 50 and 150 ng/mL of CsA (p = 0.02 and p = 0.04) as TIMP-1 decreased (p < 0.0001) in adult group; while in the fetal group, TIMP-1 level increased with treatment of 150 ng/mL (p < 0.0001). MMP-2 level increased in both adult and fetal groups (p < 0.0001). MMP-3 level decreased in adult group (p < 0.0001) but went up in fetal HGFs (p = 0.01) when treated with 150 ng/mL CsA. TIMP-2 level increased in all wells significantly when treated with CsA (p < 0.0001). The study showed that CsA affects secretion of MMPs and TIMPs. MMP-1 increment and TIMP-1 decrement were observed, which indicate more degradation of ECM. This may be due to single donor use in this study. TIMP-2 and MMP-2 were both more active when treated with CsA which may be due to the gelatinase activity of them and that in CsA gingival overgrowth. There was more inflammation rather than fibrosis.

Among several bacteria examined, an antibacterial-producing Lactobacillus strain with probiotic characteristics was selected and identified based on 16S rRNA gene sequencing. Subsequent purification and mode of action of the antibacterial compounds on target cells including E. coli were investigated. Maximum production of the antibacterial compound was recorded at 18 h incubation at 30 degrees C. Interestingly, antibacterial activity remained unchanged after heating at 121 degrees C for 45 min, 24 h storage in temperature range of 70 degrees C to room temperature, and 15 min exposure to UV light, and it was stable in the pH of range 2-10. The active compounds were inactivated by proteolytic enzymes, indicating their proteinaceous nature, and, therefore, referred to as bacteriocin-like inhibitory substances. Isolation and partial purification of the effective agent was done by performing ammonium sulfate precipitation and gel filtration chromatography. The molecular mass of the GFC-purified active compound (~3 kDa) was determined by Tris-Tricine SDS-PAGE. To predict the mechanisms of action, transmission electron microscopy (TEM) analysis of ultrathin sections of E. coli before and after antibacterial treatment was carried out. TEM analysis of antibacterial compounds-treated E. coli demonstrated that the completely altered bacteria appear much darker compared with the less altered bacteria, suggesting a change in the cytoplasmic composition. There were also some membrane-bound convoluted structures visible within the completely altered bacteria, which could be attributed to the response of the E. coli to the treatment with the antibacterial compound. According to the in vivo experiments oral administration of L. plantarum HKN01 resulted in recovery of infected BALB/c mice with Salmonella enterica ser. Typhimurium.