Effects of Lactobacillus curvatus MG5246 on inflammatory markers in Porphyromonas gingivalis lipopolysaccharide-sensitized human gingival fibroblasts and periodontitis rat model

Potent oral health benefits and teeth bleaching effects of Latilactobacillus sakei THY-B1 isolated from broccoli

The study aims to examine the rising social interest in optimizing oral health and teeth bleaching outcomes using lactic acid bacteria, driven by the increasing demand for sustaining a healthy diet and social relationships in later life. This in vitro study evaluates the antibacterial activity of selected LAB via disc diffusion and microdilution methods. Plaque formation and dental caries prevention were assessed using violet biofilm staining, scanning electron microscopy, acid production assays, glycosyltransferase, and enzymatic assays. Teeth bleaching effects were tested by treating black tea-stained artificial teeth with Lactobacillus sakei THY-B1 (L. sakei THY-B1) supernatant for two weeks. L. sakei THY-B1 effectively inhibited biofilm formation at 1.56 mg/mL for S. mutans by disrupting cell walls, reducing acid production, and inhibiting glucosyltransferase activity through the generation of hydrogen peroxide (H2O2 produced at 64.25 μM concentration per 1 g/mL CFS) and organic acids. The CFS of THY-B1 significantly reduced inflammatory markers, decreasing NO production by 22.4 % and suppressing key cytokines (IL-6, IL-1β, TNF-α) by 27.1-52.6 % in PDLF cells. Additionally, the treatment inhibited collagen-degrading MMPs (MMP-3/-8/-9/-13) by up to 44.9 %, suggesting protective effects against periodontal tissue damage. At its minimum inhibitory concentration, L. sakei THY-B1 demonstrated a superior bleaching effect compared to 3 % commercial H2O2, with a whiteness index 105.06 % higher than H2O2 after the first week of treatment. These findings suggest that L. sakei THY-B1 is a promising probiotic for oral health, offering both therapeutic advantages in managing oral pathogens and aesthetic bleaching benefits in teeth whitening. The promising results of L. sakei THY-B1 suggest its potential for integration into dental care protocols. This probiotic could enhance caries prevention and serve as a natural alternative for tooth bleaching, aligning with the growing patient preference for multifaceted and biocompatible therapeutic options.

Evaluation of the anti-inflammatory, antioxidant and regenerative effects of microbiota-derived postbiotics in human periodontal ligament mesenchymal stromal cells

OBJECTIVE

This study investigates the regenerative and protective effects of postbiotics (cell-free supernatant) derived from the Lactiplantibacillus plantarum EIR/IF-1 strain on human periodontal ligament mesenchymal stromal cells (hPDL-MSCs).

MATERIALS AND METHODS

hPDL-MSCs were isolated from periodontal ligament tissues (PDL) of wisdom teeth using enzymatic digestion and subsequently characterized through immunophenotyping. The effect of postbiotics on the viability of hPDL-MSCs was assessed using the MTT assay and flow cytometry, while their impact on cell migration was evaluated via the scratch assay. Anti-inflammatory effects of postbiotics were investigated on lipopolysaccharide (LPS, derived from Porphyromonas gingivalis)-stimulated hPDL-MSCs through Enzyme-Linked Immunosorbent Assay (ELISA). Additionally, the antioxidant effects of postbiotics were analyzed in hydrogen peroxide (H₂O₂)-induced hPDL-MSCs by measuring reactive oxygen species (ROS) levels using flow cytometry. The expression of collagen type I (COL1A1) gene was further assessed by quantitative reverse transcription PCR and immunofluorescence staining.

RESULTS

Treatment with postbiotics (250 µg/mL) significantly increased the viability and migration capability of hPDL-MSCs, while enhancing collagen production for PDL repair. Treatment with postbiotics for 24 h resulted in a 54.53 ± 2.01% reduction in intracellular ROS levels compared to untreated H2O2-induced hPDL-MSCs. Furthermore, postbiotics significantly decreased the production of pro-inflammatory cytokines (IL-8, IL-6, and IL-1β), and increased the anti-inflammatory cytokine IL-10 (2.67-fold) compared to untreated LPS-stimulated hPDL-MSCs.

CONCLUSION

Our findings indicate that postbiotics exhibit biological activity throughout all stages of the healing process, beginning with the modulation of the inflammatory response to LPS stimulation, followed by the promotion of cell migration, proliferation, and collagen synthesis. Given the unmet need for safe and adjuvant therapeutic approaches that promote comprehensive periodontal regeneration in periodontal diseases, this study presents postbiotics as a promising candidate.

CLINICAL RELEVANCE

Postbiotics could be integrated into regenerative therapies as a novel bioactive material to improve the healing and regenerative outcomes in periodontal defects by both controlling inflammation and stimulating tissue repair processes.

Development of a Postbiotic-Based Orodispersible Film to Prevent Dysbiosis in the Oral Cavity

BACKGROUND

Oral diseases affect over three billion peopleand are among the most commonly observed infections worldwide. Recent studies have shown that controlling the ecology of the oralome is more effective in reducing the risk of caries than the complete removal of both harmful and beneficial microorganisms. This work aimed to develop a strategy for preventing dysbiosis in the oral cavity by applying a postbiotic-based orodispersible film.

METHODS

Lactiplantibacillus plantarum 226V and Lacticaseibacillus paracasei L26 were cultured in De Man-Rogosa-Sharpe (MRS) broth for 48 hours, followed by centrifugation and filtration. Then, the resultant postbiotics were then subjected to various dilutions (10% (v/v), 20% (v/v), 40% (v/v), 60% (v/v) and 100% (v/v)) and co-incubated with Streptococcus mutans. Antimicrobial efficacy, minimal inhibitory concentration, the time required to inhibit S. mutans growth, and antibiofilm properties of the postbiotics were assessed. Subsequently, an orodispersible film comprising polymers and plasticizers, namely Xanthan gum, maltodextrin, and glycerol, was developed as a vehicle for postbiotic delivery. Formulation optimization, physical property evaluation, and cytotoxicity against the TR146 human oral cell line (TR146 cell line) were conducted.

RESULTS

Postbiotics demonstrated antimicrobial and antibiofilm activity against S. mutans following 24-hour co-incubation. The minimal inhibitory concentration for combined postbiotics administration was 20% (v/v). Remarkably, 79.6 ± 8.15% inhibition of biofilm formation was achieved using 100% (v/v) of the postbiotic derived from L. plantarum 226V. Incorporating postbiotics did not compromise the dissolution time of orodispersible films, all exceeding 20 minutes. Furthermore, solubility improved following postbiotic addition, facilitating ease of handling. Importantly, postbiotic-impregnated orodispersible films were non-cytotoxic when exposed to the TR146 cell line.

CONCLUSIONS

These findings underscore the potential of orodispersible films loaded with postbiotics as a promising potential intervention for oral dysbiosis.

Postbiotic potential of Bacillus velezensis KMU01 cell-free supernatant for the alleviation of obesity in mice

Attention toward the preventive effects of postbiotics on metabolic diseases has increased because of greater stability and safety over probiotics. However, studies regarding the bioactive effects of postbiotics, especially from probiotic Bacillus strains, are relatively limited. The anti-obesity effects of the cell-free culture supernatant of Bacillus velezensis KMU01 (CFS-B.vele) were evaluated using high-fat-diet (HFD)-induced mice. HFD-induced mice (n = 8 per group) received equal volumes of (1) CFS-B.vele (114 mg/kg) in PBS, (2) Xenical in PBS, or (3) PBS alone by oral gavage daily for 13 weeks. The results demonstrated that CFS-B.vele changed the gut microbiota and showed anti-obesity effects in HFD-induced obese mice. The elevated Firmicutes/Bacteroidota ratio induced by HFD was decreased in the CFS-B.vele group compared to the other groups (p < 0.05). The CFS-B.vele intervention led to the enrichment of SCFA-producers, such as Roseburia and Eubacterium, in the cecum, suggesting their potential involvement in the amelioration of obesity. Due to these changes, the various obesity-related biomarkers (body weight, fat in tissue, white adipose tissue weight and size, serum LDL-cholesterol level, hepatic lipid accumulation, and adipogenesis/lipogenesis-related gene/protein expression) were improved. Our findings suggest that CFS-B.vele has potential as a novel anti-obesity agent through modulation of the gut microbiota.

New insights into nanotherapeutics for periodontitis: a triple concerto of antimicrobial activity, immunomodulation and periodontium regeneration

Periodontitis is a chronic inflammatory disease caused by the local microbiome and the host immune response, resulting in periodontal structure damage and even tooth loss. Scaling and root planning combined with antibiotics are the conventional means of nonsurgical treatment of periodontitis, but they are insufficient to fully heal periodontitis due to intractable bacterial attachment and drug resistance. Novel and effective therapeutic options in clinical drug therapy remain scarce. Nanotherapeutics achieve stable cell targeting, oral retention and smart release by great flexibility in changing the chemical composition or physical characteristics of nanoparticles. Meanwhile, the protectiveness and high surface area to volume ratio of nanoparticles enable high drug loading, ensuring a remarkable therapeutic efficacy. Currently, the combination of advanced nanoparticles and novel therapeutic strategies is the most active research area in periodontitis treatment. In this review, we first introduce the pathogenesis of periodontitis, and then summarize the state-of-the-art nanotherapeutic strategies based on the triple concerto of antibacterial activity, immunomodulation and periodontium regeneration, particularly focusing on the therapeutic mechanism and ingenious design of nanomedicines. Finally, the challenges and prospects of nano therapy for periodontitis are discussed from the perspective of current treatment problems and future development trends.

Effects of Lactobacillus reuteri MG5346 on Receptor Activator of Nuclear Factor-Kappa B Ligand (RANKL)-Induced Osteoclastogenesis and Ligature-Induced Experimental Periodontitis Rats

Effects of culture supernatants of Lactobacillus reuteri MG5346 (CS-MG5346) on receptor activator of nuclear factor-kappa B ligand (RANKL)-induced osteoclastogenesis were examined. CS-MG5346 treatment up to 400 μg/mL significantly reduced tartrate-resistant acid-phosphatase (TRAP) activity, the phenotype biomarker of osteoclast, without affecting cell viability. CS-MG5346 inhibited the expression of osteoclast specific transcriptional factors (c-fos and nuclear factor-activated T cells c1) and their target genes (TRAP, cathepsin, and matrix metallo-proteinase-9) in a dose-dependent manner (p<0.05). The administration of L. reuteri MG5346 (2×10⁸ CFU/day) for 8 wks significantly improved furcation involvement, but no difference was observed in alveolar bone loss in ligature-induced experimental periodontitis rats. The elevated RANKL/ osteoprotegerin ratio, the biomarker of periodontitis, was significantly lowered in the gingival tissue by administration of L. reuteri MG5346 (p<0.05). L. reuteri MG5346 showed excellent stability in simulated stomach and intestinal fluids and did not have antibiotic resistance. Based on the results, L. reuteri MG5346 has the potential to be a promising probiotic strain for oral health.

Lacticaseibacillus rhamnosus MG4706 Suppresses Periodontitis in Osteoclasts, Inflammation-Inducing Cells, and Ligature-Induced Rats

Periodontitis is a chronic inflammatory disease characterized by tooth loss due to inflammation and the loss of alveolar bone. Periodontitis is closely related to various systemic diseases and is emerging as a global health problem. In this study, we investigated the anti-inflammatory effect of lactic acid bacteria (LAB) in vitro on Porphyromonas gingivalis (P. gingivalis) LPS-activated RAW264.7 and human gingival fibroblasts-1 (HGF-1) cells and the anti-osteoclastogenic effect of LAB on RANKL-induced RAW264.7 cells. All LAB strains (Lacticaseibacillus rhamnosus MG4706, MG4709, and MG4711) inhibited nitric oxide (NO)/inducible nitric oxide synthase (iNOS) in P. gingivalis LPS-activated RAW264.7 cells and pro-inflammatory cytokines (IL-1β and IL-6) and matrix metalloproteinase (MMP-8 and MMP-9) in HGF-1 cells. In addition, LAB treatment inhibited osteoclastogenesis by reducing tartrate-resistant acid phosphatase (TRAP) activity and cathepsin K (CtsK) through the downregulation of nuclear factor of activated T cells cytoplasmic 1 (NFATc1) and c-fos gene expression in RANKL-induced RAW264.7 cells. Administration of MG4706 alleviated alveolar bone loss indices and reduced the gene expression of IL-1β, IL-6, MMP-8, MMP-9, and RANKL/OPG ratio in gingival tissue. In conclusion, L. rhamnosus MG4706 has the potential to alleviate periodontitis.

The Anti-Cancer Potential of Heat-Killed Lactobacillus brevis KU15176 upon AGS Cell Lines through Intrinsic Apoptosis Pathway

Recent research has focused on the anti-cancer properties of Lactobacillus strains isolated from fermented foods. Their anti-cancer effects are caused by the apoptosis induction in cancer cells. However, sepsis, which can occur when cancer patients consume living organisms, can cause serious conditions in patients with reduced immunity because of cancer. Therefore, this study was conducted using heat-killed Lactobacillus brevis KU15176 (KU15176). To determine the relationship between inflammation and cancer, the anti-inflammatory effect of KU15176 was evaluated using a nitric oxide (NO) assay. Then, 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay was conducted to select cancer cells that showed the anti-proliferative effect of KU15176. Next, reverse transcription-polymerase chain reaction (RT-PCR), 4′,6-diamidino-2-phenylindole (DAPI) staining, flow cytometry, and caspase colorimetric assay were performed. As a result, it was confirmed that KU15176 could cause the increasing expression of apoptosis-related genes (Bax, caspase-3, and caspase-9), DNA breakage, effective apoptosis rate, and increased caspase activity in the human stomach adenocarcinoma (AGS) gastric cancer cell line. In conclusion, these results suggest a potential prophylactic effect of KU15176 against cancer.

Probiotics as Potential Biological Immunomodulators in the Management of Oral Lichen Planus: What's New?

Oral lichen planus (OLP) is a T cell-mediated chronic inflammatory disorder with multifactorial aetiology and malignant transformation potential. Despite the treatments so far identified, new tailored and safe specific measures are needed. Recently, human microbiota imbalance has been linked to several immune-mediated diseases, opening new therapeutic perspectives for probiotics; besides their ability to directly interact with the host microbiota, they also display a strain-specific immune-modulatory effect. Thus, this non-systematic review aims to elucidate the molecular pathways underlying probiotic activity, mainly those of Lactobacilli and Bifidobacteria and their metabolites in OLP pathogenesis and malignant transformation, focusing on the most recent in vitro and in vivo research evidence. Findings related to their activity in other immune-mediated diseases are here included, suggesting a probiotic translational use in OLP. Probiotics show immune-modulatory and microbiota-balancing activities; they protect the host from pathogens, hamper an excessive effector T cell response, reduce nuclear factor-kappa B (NF-kB) signalling and basal keratinocytes abnormal apoptosis, shifting the mucosal response towards the production of anti-inflammatory cytokines, thus preventing uncontrolled damage. Therefore, probiotics could be a highly encouraging prevention and immunotherapeutic approach for a safer and more sustainable OLP management.