Journal of Oral Microbiology最新文献

Background: Adjunctive therapies have been proposed to enhance periodontal outcomes by modulating the subgingival microbiome. However, the microbiological effects of probiotic supplementation in diabetic patients with periodontitis remain unclear, particularly when assessed using high-resolution sequencing methods.

Aim: To evaluate the effect of a Limosilactobacillus reuteri as an adjunct to subgingival instrumentation on the subgingival microbiome in the treatment of periodontitis in patients with diabetes.

Methods: This was a secondary analysis of a randomized, triple-blind, placebo-controlled clinical trial. Forty patients with stage II-III periodontitis and diabetes received subgingival instrumentation and either L. reuteri lozenges (n = 19) or placebo (n = 21) for 3 months. Subgingival samples were collected at baseline, 3, and 6 months. The V3-V4 region of the 16S rRNA gene was sequenced and analyzed using QIIME2. Alpha diversity was analyzed with mixed-effects models, beta diversity with PERMANOVA, and differential abundance with linear models.

Results: A total of 116 high-quality samples were included. Alpha and beta diversity metrics did not show significant differences between groups or across time points. L. reuteri was detected inconsistently in the subgingival microbiome, with low relative abundances and no sustained presence over time. No bacterial species exhibited significant changes in differential abundance between the probiotic and placebo groups over time.

Conclusions: Adjunctive L. reuteri supplementation did not significantly alter subgingival microbiome diversity or composition over 6 months.

Background: Coaggregation is proposed to enhance oral biofilm development. This study aims to evaluate an innovative high-throughput spectrophotometric method for quantifying coaggregation, which relies upon dome-shaped wells (DSWs) in microplates to partition coaggregates in cell suspensions, and compare its utility against other established methods.

Materials and methods: Batch-cultured cells of Streptococcus gordonii DL1 and Actinomyces oris T14V were suspended individually in coaggregation buffer (Coag-B) or buffered KCl (B-KCl) for coaggregation experiments. Multiple methods were used to assess coaggregation between S. gordonii DL1 and A. oris T14V in the two buffers: the high-throughput spectrophotometric assay using modified 24-well microplates; visual aggregation assays; confocal microscopy; and cuvette-based spectrophotometry.

Results: In either buffer, S. gordonii DL1 and A. oris T14V coaggregated strongly in visual tube-based assays, although the coaggregates were typically larger and more condensed in B-KCl. This observation was supported by microscopy and cuvette-based measurements. Compared with other well/buffer combinations, coaggregation was most strongly and reproducibly detected in endpoint and kinetic studies when cells were suspended in B-KCl and added to DSWs.

Conclusion: Using DSWs in combination with B-KCl provided a high-throughput quantitative approach to study coaggregation between S. gordonii DL1 and A. oris T14V.

Objective: To systematically review the association between oral dysbiosis and pregnancy-related complications and to quantitatively assess differences in oral microbial alpha diversity between preterm birth (PTB) and term birth (TB).

Material and methods: A systematic search was conducted in July 2025 following PRISMA 2020 guidelines and registered in PROSPERO. Studies published between 2015 and 2025 assessing oral microbiota composition, alpha/beta diversity, or taxa abundance in relation to preeclampsia, gestational diabetes mellitus, preterm birth, low birth weight, mental health disorders, or pregnancy loss were included. Due to heterogeneity in study design, microbiome metrics, and outcome definitions, meta-analysis was restricted to studies comparing Shannon alpha diversity between PTB and TB. Study quality was assessed using the Newcastle-Ottawa Scale and the Joanna Briggs Institute checklist.

Results: Twenty-one studies met the inclusion criteria, including cohort, case-control, and cross-sectional designs; four were included in the meta-analysis. Pregnancy complications were commonly associated with altered oral microbial profiles, characterized by reduced alpha diversity, changes in beta diversity, and increased abundance of genera such as Prevotella, Veillonella, and Porphyromonas. The meta-analysis suggested a directional trend toward altered alpha diversity in adverse pregnancy outcomes.

Conclusions: Overall, the findings support a potential association between oral dysbiosis and pregnancy-related complications; however, this evidence is limited by the small scale and heterogeneity of the available studies. These results highlight the oral microbiome as a biologically plausible contributor to adverse maternal and neonatal outcomes and a promising focus for future mechanistic and translational research.

Background: The oral bacterium Aggregatibacter actinomycetemcomitans (Aa) is associated with infectious diseases treated with antibiotics, but specific recommendations for antimicrobial susceptibility testing (AST) of the species do not yet exist. Objective To evaluate the possibility to perform AST of Aa following EUCAST guidelines using FAA-HB and 20 h incubation.

Method: Twenty-nine Aa strains were analysed using disk diffusion on FAA-HB media from three manufacturers. Plates with with ampicillin and azithromycin disks were incubated in 5% CO₂ and anaerobic conditions and examined after 20 and 44 h. Strains were additionally tested with the agar dilution method, and inhibition zone diameters (IZD) were correlated to the minimal inhibitory concentrations.

Results: FAA-HB agar supported sufficient growth of Aa after 20 h incubation in 5% CO₂. No significant differences in IZD were found between the three media tested. Prolonged incubation (44 h) increased IZD, but 20 h incubation was adequate for reproducible results. Incubation in 5% CO₂ was superior to anaerobic conditions.

Conclusion: Incubation in 5% CO2 and reading after 20 h incubation resulted in the best correlation between FAA-HB media from three manufacturers. The EUCAST disk diffusion method with FAA-HB for AST of Aa may be crucial for future standardization and development of clinical breakpoints for this species.

Background: Global demographic aging is intensifying the burden of age-related diseases. Cellular senescence and the accompanying senescence-associated secretory phenotype (SASP) act as key drivers of disease progression by mediating chronic inflammation. As the second largest microbial community in the human body, the oral microbiome occupies a central position in systemic aging pathologies, and its dysbiosis and interaction with SASP are critical in this process. An imbalanced oral microbiota contributes to systemic chronic conditions via metabolic activities, virulence factor release, and immune system activation, while SASP serves as a central molecular mediator linking microbial dysbiosis to chronic inflammation, with well-recognized involvement in inflammatory bowel disease, bone disorders, and neurodegenerative conditions.

Objective: This review aims to examine the mechanism by which oral pathogens directly modulate SASP secretion via microbial metabolites and virulence factors to drive the pathogenesis of age-related diseases, propose a unifying framework of the 'oral microbiome-SASP-aging' axis, summarize therapeutic interventions targeting this axis, and suggest future development directions for precise modulation of the 'microbiome-SASP-aging' cascade.

Design: A narrative review was conducted to synthesize and analyze existing literature on the interplay between the oral microbiome, SASP, and age-related diseases. The review focused on mechanisms of oral pathogen-mediated SASP modulation, therapeutic strategies targeting the 'oral microbiome-SASP-aging' axis, and potential advancements in precise therapeutic delivery and combinatorial therapies.

Results: The 'oral microbiome-SASP-aging' axis serves as a unifying framework for these pathologies. SASP inhibitors, probiotics, and traditional Chinese medicine (TCM) targeting this axis show promise for age-related disease management. Additionally, spatiotemporally precise delivery systems and probiotic-TCM combinatorial therapies are proposed for precise modulation of the 'microbiome-SASP-aging' cascade.

Conclusions: The 'oral microbiome-SASP-aging' axis is a pivotal pathway driving age-related diseases. Therapeutic strategies targeting this axis hold significant promise for clinical management of these diseases. Future advancements in spatiotemporally precise delivery systems and combinatorial therapies are anticipated to enable precise modulation of the 'microbiome-SASP-aging' cascade, offering novel avenues for the prevention and treatment of age-related diseases.

Introduction: Oral microbiota dysbiosis is linked to cardiovascular disease, and oral pathogens have been detected in atherosclerotic plaques. We aimed to investigate the relationship between the oral microbiota and carotid atherosclerosis, and the occurrence of oral pathogens in plaques.

Patients and methods: Oral swab and saliva samples from patients with severe carotid atherosclerosis (≥50% stenosis) were compared with those from controls. The oral microbiome was analyzed by 16S rRNA amplicon sequencing targeting the V3‒V4 region. Carotid plaques were investigated for five oral bacterial species by qRT-PCR.

Results: Compared with controls, patients exhibited different inter-individual (beta) diversity (r = 0.02, p = 0.002), reduced intra-individual (alpha) diversity (p = 0.026) and 22 bacterial genera differed in relative abundance. Furthermore, abundances of five bacterial genera, including Eikenella, were increased in patients with recent cerebrovascular symptoms compared to asymptomatic patients. Eikenella corrodens was detected in all 30 carotid plaques.

Conclusion: Oral microbiota diversity and composition differ between patients with carotid atherosclerosis and controls. A higher relative abundance of the genus Eikenella in symptomatic versus asymptomatic patients and the detection of the species Eikenella corrodens in all carotid plaques, might suggest that Eikenella is important in atherogenesis and plaque instability. Oral Eikenella could possibly serve as a potential new biomarker.

Background/objective: Gastric cancer (GC) is a major cause of cancer mortality worldwide. We evaluated whether oral microbiota could be sensitive, specific, and non-invasive markers for early GC detection.

Materials and methods: Saliva samples were analyzed using 16S rRNA sequencing, and oral microbial markers were validated using an internal validation dataset. Machine learning was used to identify key genera, and functional associations were inferred using Kyoto Encyclopedia of Genes and Genomes pathway and ortholog analyses. Blood samples were also collected, and plasma cytokines were quantified by enzyme-linked immunosorbent assay (ELISA) for pathway-level interpretations.

Results: Eight genera-Lautropia, Megasphaera, Ralstonia, Pseudomonas, Peptostreptococcus, Anaerovorax, Fusobacterium, and Neisseria-were validated as diagnostic microbial markers (area under the receiver operating characteristic curve [AUC] = 0.91). Megasphaera and Ralstonia were enriched in GC, whereas Lautropia was depleted and associated with reduced risk. These genera may be functionally linked to pathways involved in GC progression, including NF-κB, IL-6, STAT3, TGF-β1, and Smad2/3. The proposed classification method effectively identified early-stage and tumor-marker-negative GCs, underscoring its clinical translation potential.

Conclusions: Oral microbial markers, including Ralstonia, Megasphaera, and Lautropia, may serve as non-invasive diagnostic markers for GC and may be related to carcinogenic signaling activity.

Dental caries is a biofilm-mediated disease that arises from polymicrobial dysbiosis in dental plaque. Among these microorganisms, Streptococcus mutans plays a prominent role because of its strong capacity to metabolize fermentable carbohydrates into organic acids that drive enamel demineralization. Central to this process is pyruvate, a key metabolic intermediate that connects glycolysis, energy production, biosynthesis, and stress adaptation. Pyruvate metabolism in S. mutans directs carbon flow into various pathways that contribute to its cariogenic potential, including acidogenesis, biofilm formation, and oxidative stress tolerance. This review explores the multifaceted roles of pyruvate in S. mutans, emphasizing its involvement in the production of lactate, acetate, formate, and branched-chain amino acids. We also discuss the regulatory mechanisms that control pyruvate metabolism, such as the Pta-Ack pathway, LrgAB-mediated pyruvate transport, and transcriptional regulation by CcpA/CodY. Furthermore, we highlight promising strategies for caries prevention, including the targeting of pyruvate metabolism using natural compounds and metabolic inhibitors. Future research should focus on elucidating the regulatory networks governing pyruvate metabolism, the metabolic byproducts, and the impact of disrupting pyruvate-based metabolic crosstalk in polymicrobial biofilms. Understanding how pyruvate functions as a carrier or precursor metabolite in central carbon metabolism of S. mutans and its regulation of survival and metabolic processes will have significant implications for caries prevention.

Background: Chronic intestinal inflammation is a hallmark of inflammatory bowel disease (IBD). Studies suggest that salivary bacteria associated with periodontitis may exacerbate colitis, but the specific contributory microbes and mechanisms remain unclear.

Patients and methods: We analyzed stool samples from 28 IBD patients and 21 controls. Bacterial DNA was extracted and quantified using qPCR targeting Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans). In a murine model, C57BL/6 mice received DSS followed by daily oral gavage with A. actinomycetemcomitans. Disease activity, histopathology and the gut microbiota were evaluated.

Results: Oral administration of A. actinomycetemcomitans exacerbated inflammatory symptoms in DSS-induced colitis. The bacterium was detectable in intestinal tissue transiently following high-dose oral administration during the inflammatory phase. Following high-dose gavage, bacterial DNA was transiently detectable in intestinal tissue during inflammation. This treatment was associated with reduced expression of the tight junction protein ZO-1 and mucin MUC-2, elevated inflammatory mediators, and altered gut microbial community structure, including an expansion of taxa associated with dysbiosis.

Conclusion: In a murine colitis model, A. actinomycetemcomitans exposure was associated with worsened disease severity, coinciding with impaired barrier integrity, heightened inflammation and gut microbiota alterations. These exploratory findings highlight the potential role for specific periodontal microbes in modulating intestinal inflammation and warrant further investigation.