Hwang J, et al. J Periodontal Implant Sci. 2024 Jul;54:e17. https://doi.org/10.5051/jpis.2304520226

Dental clinicians and researchers have recently recommended oral microbial examinations to more accurately diagnose and treat oral diseases, including periodontitis and dental caries. Theoretical and experimental evidence suggests that oral microbiota may also be associated with non-oral diseases, such as gastrointestinal and extra-gastrointestinal diseases. This review highlights studies demonstrating microbial alterations in the oral cavity associated with malignant tumors including gastric, colorectal, esophageal, and lung cancers, implying that these alterations may serve as early indicators for non-invasive diagnosis and risk assessment of cancer development. Furthermore, we addressed the implications of oral microbial co-occurrence with malignant tumors, such as Streptococcus anginosus, Fusobacterium nucleatum, and Veillonella parvula, which are recognized as tumor-enriched oral pathogens involved in the development and progression of cancers in the stomach, colon, and lungs, respectively. Notably, we explored the immune and inflammatory mechanisms underlying reciprocal interactions between oral microbiota and tumors, underscoring that targeting these mechanistic pathways can contribute to preventing cancer development.

Objectives: Probiotic supplementation, integrated into routine oral care, may improve periodontal status and metabolic function. In this retrospective longitudinal study, we evaluated the efficacy of probiotics added to non-surgical periodontal treatment (NSPT) in reducing the burden of oral pathogens and improving metabolic dysfunction. Methods: Twenty outpatients with chronic periodontitis and at least one metabolic abnormality underwent NSPT with daily probiotic supplementation for 12 weeks. Baseline and post-intervention assessments included clinical indices, blood pressure, and blood biomarkers (HbA1c, fasting glucose, and lipid profiles), with analysis of oral pathogens using qPCR. Results: Among the 13 eligible participants, probiotics with NSPT resulted in significant reductions in HbA1c (-0.3%, p<0.001), and systolic blood pressure (-9.6 mmHg, p<0.001), and Tannerella forsythia (p<0.05) levels, along with decreasing trends in other pathogens. However, no significant changes were noted in periodontal indices, including probing pocket depth and bleeding on probing, nor in lipid profiles. Conclusions: These f indings suggest that probiotic supplementation with NSPT may improve glycemic control and systolic blood pressure but may have a limited effect on periodontal indices, warranting larger trials to confirm its potential.

Background/Objectives: Type 2 diabetes mellitus (T2DM) is closely associated with obesity, insulin resistance, and gut microbiota dysbiosis. This study investigated the effects of a probiotic combination of Lactiplantibacillus plantarum DM083 and Lacticaseibacillus rhamnosus DM163 on glycemic control, insulin resistance, gut microbiota composition, and metabolic parameters in high-fat-diet (HFD)-induced obese mice. Methods: Male C57BL/6 mice were fed a 60% HFD for 8 weeks and subsequently administered DM083/163 (1 × 10⁹, 5 × 10⁹, or 1 × 10¹⁰ CFU/day) or metformin (250 mg/kg/day) for 12 weeks. Glucose metabolism, insulin resistance, hepatic gene expression, gut microbiota composition, and fecal short-chain fatty acids (SCFAs) were evaluated. Results: DM083/163 supplementation at 1 × 10¹⁰ CFU/day significantly reduced fasting blood glucose, HbA1c, oral glucose tolerance test area under the curve, and HOMA-IR compared with the HFD control group (p < 0.05). Hepatic expression of the gluconeogenic genes Pck1 and G6pc was significantly downregulated, accompanied by reduced hepatic and serum TNF-α levels. Gut microbiota analysis revealed significant overall differences in beta diversity across groups (PERMANOVA, R² = 0.262, p = 0.001), driven primarily by diet, with a trend toward a reduced Bacillota/Bacteroidota ratio in the high-dose group. Conclusions: DM083/163 supplementation improved glycemic control and insulin resistance in HFD-induced obese mice. These effects were associated with suppression of hepatic gluconeogenesis, attenuation of inflammation, and increased SCFA production, findings that are consistent with, but do not establish, modulation of the gut–liver axis. These findings support the potential use of DM083/163 as a probiotic intervention for obesity-associated T2DM.

Probiotic strains with multifunctional skin-beneficial properties represent promising candidates for next-generation cosmetic ingredients. In this study, a systematic stepwise screening strategy was applied to an in-house bacterial library comprising 302 isolates to identify candidates with antioxidant, anti-inflammatory, antimicrobial, wound-healing, and skin barrier-supportive activities. From this library, 33 strains were selected based on preliminary assessments and subjected to comprehensive in vitro evaluation. Cell viability and cytotoxicity assays confirmed the safety of all selected strains in RAW264.7 macrophages and HaCaT keratinocytes. Several strains exhibited strong DPPH radical scavenging activity and significantly inhibited nitric oxide production in LPS-stimulated macrophages. Among the selected candidates, Lacticaseibacillus rhamnosus DM073 demonstrated the most potent anti-inflammatory activity, whereas Lactiplantibacillus plantarum DM043 exhibited the greatest wound-healing capacity. All five selected strains displayed antimicrobial activity against Cutibacterium acnes. Furthermore, selected strains, particularly Lactiplantibacillus plantarum DM175 and Ligilactobacillus salivarius DM079, enhanced the expression of skin barrier-related genes, including zonula occludens-1 (ZO-1), occludin (OCLN), claudin-1 (Cla-1), and filaggrin (FLG), and partially restored their expression under TNF-α/IFN-γ-induced inflammatory conditions. Selected strains also reduced the expression of inflammatory chemokines in stimulated keratinocytes. Collectively, these findings demonstrate that the selected probiotic strains possess complementary multifunctional activities associated with skin health. In particular, DM073 exhibited superior anti-inflammatory activity, DM043 showed strong wound-healing potential, and DM175 demonstrated remarkable skin barrier-supportive effects. These strain-specific properties support their potential application in the development of probiotic-derived postbiotic cosmetic ingredients for skin soothing, barrier reinforcement, skin recovery, and microbiome-friendly skincare formulations. Further studies are warranted to evaluate their efficacy and safety in advanced skin models and clinical cosmetic applications.

Objectives: This pilot trial evaluated the adjunctive effects of combined Lacticaseibacillus rhamnosus DM163 and Lactobacillus plantarum DSR920 following scaling and root planing (SRP) on periodontal parameters, oral microbiota, and safety in patients with mild gingivitis. Methods: Thirty participants with mild gingivitis were enrolled in this single-center, double-blind, randomized pilot trial. After SRP, the participants received either probiotics or a placebo for 12 weeks. Clinical parameters, oral bacteria detected by qPCR, serum inflammatory biomarkers, and safety outcomes were assessed. Results: Twenty-seven participants were included in the analysis (test group n=14, placebo group n=13). No statistically significant between-group or within-group changes were observed in any of the clinical periodontal parameters. Treponema denticola increased in the 6-week mouthwash samples in the placebo group (p=0.005), while Fusobacterium nucleatum increased in the 12-week plaque samples in the test group (p=0.009). Overall, no consistent reduction in major periodontal pathogens was observed. Most serum inflammatory biomarkers remained below the detection limits, and no serious adverse events occurred. Conclusions: In the present post-SRP mild gingivitis setting, the adjunctive use of probiotics was well tolerated but did not demonstrate statistically significant clinical or microbiological effects. Future trials should optimize baseline standardization and statistical power, and incorporate gingival crevicular fluid analysis. Trial registration: KCT0009762.