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At least 19 recordsLinked to original sources
PubMed2026

Causal Relationships Between Oral Microbiota and Inflammatory Skin Diseases.

INTRODUCTION AND AIMS: The oral microbiome has been increasingly linked to systemic inflammation and immune dysregulation, but whether specific oral bacteria causally contribute to inflammatory skin diseases remains unclear due to confounding and reverse causation. This study aimed to assess the causal effects of 43 oral microbiota taxa on the risk of five inflammatory skin diseases using a Mendelian randomization (MR) approach. METHODS: We performed a two-sample MR analysis using genetic instruments for oral microbiota derived from publicly available genome-wide association studies and outcome data from the FinnGen consortium. Causal effects of oral taxa on systemic lupus erythematosus, vitiligo, pemphigus, localized scleroderma, and dermatitis herpetiformis were estimated. The inverse-variance weighted method served as the primary analysis, complemented by sensitivity analyses to evaluate horizontal pleiotropy, heterogeneity, and reverse causality. RESULTS: MR analyses identified several putative causal associations between oral microbiota and inflammatory skin diseases. Genus Granulicatella and an unknown Streptococcus species (ASV0009) showed causal effects on systemic lupus erythematosus. Family Lachnospiraceae_[XIV] and an unknown Rothia species (ASV0016) were associated with vitiligo. Five oral microbiota taxa demonstrated causal associations with pemphigus. Actinomyces species micronuciformis was linked to localized scleroderma. Order Fusobacteriales and an unknown Neisseria species (ASV0004) were associated with dermatitis herpetiformis. No significant heterogeneity or horizontal pleiotropy was detected in sensitivity analyses. CONCLUSION: This MR study provides genetic evidence supporting a causal role of specific oral bacteria in the development of several inflammatory skin diseases, highlighting the oral microbiome as a potential contributor to cutaneous autoimmunity and inflammation. CLINICAL RELEVANCE: Our findings highlight the putative role of the oral microbiome as a plausible candidate for mechanistic and clinical investigations into the prevention or adjunctive management of selected inflammatory skin diseases. However, oral hygiene improvement, targeted antimicrobials, and other microbiota-directed interventions were not directly tested in this MR study and remain hypothetical strategies requiring validation in experimental and clinical studies.

Humans↗
PubMed1978

Genital occurrence of oral microbiota.

Recent studies indicate that tonsillar gonococcal infection or colonization is fairly common. Carriage rates of about 8% have been found. These studies also indicate that oro-genital contacts are common. Since very little is known about the amount of oral microbiota transmitted to the genitals, we have studied the occurrence of oral streptococci and Neisseria species in urethra and cervix. Among 128 patients attending an STD-clinic we found 10 carriers of oral streptococci, one Streptococcus mitior, four Streptococcus sanguis, one Streptococcus mutans and four Streptococcus salivarius and case of urethritis due to Neisseria menigitidis. Seventy-three of the patients had recently had their genitals exposed to the oral flora of their partners. Despite the heavy contamination with oral microbiota that can be assumed to occur in these cases, there seems to be no colonization of the genitals with oral microbiota.

Adult↗
PubMed2026

Characterization of the oral microbiota and antimicrobial resistance genes in shelter dogs in Japan.

Companion animals can serve as reservoirs of antimicrobial resistance genes and zoonotic microorganisms, yet information on shelter dogs remains limited. This study characterized the oral microbiota and screened for antimicrobial resistance genes in shelter dogs in Japan. Oral swabs were collected from 81 dogs, microbial genomic DNA was extracted, bacterial communities were profiled by 16S rRNA gene amplicon sequencing, and antimicrobial resistance genes were screened by PCR. We detected genes conferring resistance to several antimicrobial classes, including β-lactams, tetracyclines, macrolide-lincosamide-streptogramin B, phenicols, and sulfonamides. cfxA was detected in all 81 samples, followed by sul1 (66/81), tet(M) and sul2 (65/81), floR (39/81), mecA (17/81), and erm(B) (15/81). We identified potentially pathogenic genera including Capnocytophaga, Pasteurella, Fusobacterium, Campylobacter and Corynebacterium. Microbiome analysis revealed that at the phylum level, Pseudomonadota and Bacteroidota were the most dominant, while Porphyromonas, Frederiksenia and Moraxella were the most prevalent genera. Our findings highlight that (i) the oral microbiota of shelter dogs broadly resembles that reported in companion dogs and (ii) shelter dogs represent an overlooked reservoir of clinically relevant antimicrobial resistance genes and potentially zoonotic bacteria. Therefore, it is necessary to include shelter animals in antimicrobial resistance surveillance programs to capture any potential gaps in the antimicrobial resistance prevalence in companion animals and prevent dissemination of resistant bacteria to humans following adoption of shelter dogs and cats.

antimicrobial resistance gene↗
PubMed1992

Humoral IgG antibodies to oral microbiota in a population at risk for root-surface caries.

Mutans streptococci have been strongly implicated in the initiation of dental caries on coronal surfaces. Their role in development of root-surface caries is less clear. The etiologic agents of both types of dental caries are likely to elicit systemic immune responses. The objective of the present study, therefore, was to study the association of clinical variables of disease with humoral IgG antibodies to nine oral micro-organisms in 314 adult subjects, aged 45-65 years, who were at risk for root-surface caries. Antibody activity to Streptococcus mutans strain Ingbritt, S. mutans/S. sobrinus GTFs, S. faecalis strain 19433, Actinomyces viscosus strain WVU 626, Actinomyces naeslundii strain 12, Lactobacillus casei, Actinobacillus actinomycetemcomitans strain Y4, Porphyromonas gingivalis strain 381, Eikenella corrodens strain 1073, and Wolinella recta strain 371 was measured by ELISA. Pearson correlation coefficients among log10 antibody levels within subjects revealed marked positive correlations among subgingival bacteria, generally weak positive correlations among supragingival micro-organisms, and no correlations between elements of the supragingival battery with the subgingival battery. IgG antibody levels to mutans streptococcal antigens were significantly correlated with subject DMF scores (r = 0.23; p less than 0.0001). No significant correlation was seen between DMF scores and antibody to any other supragingival micro-organism tested. Further relationships between levels of S. mutans antibody and individual clinical variables were analyzed by step-wise multiple linear regression, resulting in a model that was highly significant (p = 0.0001), with an r2 = 0.14. Numbers of missing teeth, coronal caries, root-surface caries, and root-surface restorations were each positively associated with antibody levels to mutans streptococci.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed2026

Oral and gut microbiota profiles in patients with locally advanced rectal cancer with varying responses to neoadjuvant chemoradiotherapy.

Recent research has focused on gut bacteria in colorectal cancer, but the influence of other microbiota, including oral and nonbacterial gut microbiota, on treatment efficacy remains insufficiently explored. This study aimed to investigate their relationship with the efficacy of neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC). Saliva and fecal samples were collected from patients with LARC before treatment. Shotgun metagenomic sequencing was used to profile bacterial, archaeal, eukaryotic, and viral taxonomic groups and to examine oral and gut microbial functions. An artificial intelligence-based prediction model was developed by integrating oral and gut microbiome data with clinical information. Statistical analyses compared diversity and response-associated microbial features between responders and non-responders to nCRT. Response-associated differences were observed in bacterial and nonbacterial taxonomic profiles and in oral and gut microbial functional profiles. In the internal test subset, the integrated analysis yielded an observed AUC of 0.917. Given the small cohort and the exploratory comparison of candidate classifiers, this estimate requires confirmation in larger, independent cohorts. Baseline oral and gut microbiome profiles were associated with response to nCRT. Integrating microbiome and clinical features showed potential for response prediction, but the model remains exploratory and requires validation in larger, independent cohorts before clinical application. Retrospectively registered on 01/08/2026, NCT07346729.

Aged↗
PubMed1976

Nutritional determinants of the ecology of the oral flora.

Consideration of nutritional factors as determinants of oral microbial ecology leads to the conclusion that endogenous factors play a dominant role. It is the interactions between specific microorganisms and nutritional and other factors provided by the host that selectively determine the kinds of microorganisms which willinitially reside in the oral cavity and the sites which they will colonize. The persistence of these original "colonists" in their respective ecologic niches will depend in part on the accessibility of endogenous nutrients variously provided by saliva, tissue exudates, crevicular fluids, or degenerating host cells. It will also depend on their response to and interaction with microorganisms which immigrate to that site subsequently. The microbial ecology of a given site is therefore rarely uncomplicated, the notable exception occurring at the most microscopic level where one may encounter microcolonies of individual species within more heterogenous populations of microorganisms. The extent of this heterogeneity quantitatively and qualitatively is a reflection of the degree to which the interactions between the resident flora and the new arrivals, plus the local environmental changes which they both generate, serve to promote or to discourage the survival and growth of the individual species. This element of heterogeneity in a dynamic system with its inherent potential for variation makes it possible for relatively minor changes in local environmental conditions to result in significant differences in the microflora between one site and another even though they may be in close proximity to each other. Once this concept is appreciated it becomes easy to understand how disease processes such as dental caries may affect specific areas of a tooth while nearby areas are unaffected. The effects of exogenous nutrients on the ecology of the oral microbiota, nevertheless cannot be ignored. The diet may modulate such endogenous factors as the salivary secretions and the local resistance of the gingival tissues to infections. Although at our present state of knowledge the direct influence of dietary proteins and fats on the oral microbiota is thought to be of relatively minor consequence, dietary carbohydrates are of major ecological significance. Dietary sugars provide readily available substrates for the oral microorganisms, most of which depend on carbohydrates for energy sources. The metabolism of dietary sucrose by S. sanguis and S. mutans with the productions of acids and intracellular and extracellular polysaccharides has specific influence on the microbial composition, metabolic activities, and mass of coronal plaque. The ready availability of dietary carbohydrates undoubtedly influences the microflora of other parts of the oral cavity as well, eic species or indirectly through the interactions of other organisms with them...

Adhesiveness↗
PubMed1992

Microbiological testing in the diagnosis of periodontal disease.

The oral microbiota plays a primary role in the initiation and progression of the most common forms of periodontal disease. Because of the multiplicity of factors that control the establishment and long-term evolution of the oral microbiota, a great deal of heterogeneity exists in the composition of the periodontal microbiota among individual subjects. Despite these individual differences and the complex interactions between bacteria and the host and among bacteria, an association has been demonstrated between certain species and various forms of periodontal disease. However, the predictive value of either positive or negative tests for selected bacterial species has not proved to be high enough for routine use in clinical practice. Nevertheless, bacteriological tests have been of value in the management of patients with juvenile periodontitis and refractory forms of periodontal disease. The increasing availability of diagnostic laboratory services and diagnostic kits for office use will make it easier for the practitioner to select appropriate antimicrobial treatments and monitor patients undergoing antimicrobial therapy.

Bacteria↗
PubMed2025

A high-quality genomic catalog of the human oral microbiome broadens its phylogeny and clinical insights.

The oral microbiome is increasingly linked to human health. To further examine this microbial community, we present the human reference oral microbiome (HROM), with 72,641 high-quality genomes from 3,426 species, including 2,019 previously unidentified species, improving metagenomic sequence read classification over existing catalogs. Notably, HROM unveils 1,137 previously uncharacterized candidate phyla radiation (CPR) species, establishing Patescibacteria as the most prevalent phylum in the oral microbiota and distinct from environmental Patescibacteria. Additionally, an oral CPR subclade is associated with periodontitis, complementing Porphyromonas gingivalis in predicting disease. Finally, comparing HROM with reference genomes of the gut microbiome reveals taxonomic and functional divergence between these microbiomes. HROM contains 42 ectopic oral species, and their relative abundance in gut microbiota is predictive of intestinal, cardiovascular, and liver diseases. Thus, HROM offers an expanded view of the oral microbiome and highlights the clinical importance of further examining the links between oral microbes and systemic disorders.

Humans↗
PubMed2026

The Oral Microbiome of King Richard III of England.

OBJECTIVES: Metagenomic investigations of ancient dental calculus provide insights into oral health, disease, and diet. Here, we analyze the dental calculus metagenome of King Richard III of England (1452-1485). MATERIALS AND METHODS: Dental calculus DNA was extracted from three teeth of King Richard III and shotgun sequenced to a depth of nearly 400 million reads. The metagenomic data were taxonomically profiled and compared to new and previously published dental calculus metagenomes from England, Ireland, the Netherlands, and Germany spanning the Neolithic to the present. Sequencing data were de novo assembled, and metagenome-assembled genomes assigned to the genus Tannerella were investigated for phylogenetic relatedness and virulence. Putative dietary DNA was assessed for authenticity. RESULTS: The dental calculus of King Richard III was well-preserved and yielded an exceptionally high quantity of DNA. Oral microbiome species diversity fell within the range previously observed among other northern European populations, suggesting that a royal lifestyle and a rich diet did not substantially impact his oral microbiota. The reconstructed Tannerella genomes contained many virulence factors found today among oral Tannerella species. No putative dietary DNA could be authenticated. DISCUSSION: The dental calculus of King Richard III produced one of the richest ancient oral metagenomes published to date, yet the species diversity was indistinguishable from that of commoners living in northern Europe over the last 7000 years. Insufficient plant and animal DNA were recovered to investigate diet, suggesting that dental calculus may not be a sufficient source of dietary DNA even when exceptionally well-preserved.

Humans↗
PubMed1992

Monitoring the periodontal microbiota as an adjunct to periodontal therapy: rationale, interpretation of test results and application to patient management.

Recent developments in our understanding of the relationship of the oral microbiota to periodontal diseases have led to improved approaches to controlling the pathogenic influence of certain bacterial species. In addition to non-specific control of bacterial accumulations in the sulcus region, antibiotics may be useful in suppressing persistent species with pathogenic potential. This approach is indicated in cases that do not respond adequately to mechanical plaque control measures or certain categories of periodontal diseases likely to be caused by a specific infection. Monitoring the composition of the microbiota before, during and after antimicrobial therapy is helpful in the selection of appropriate antimicrobial agents, monitoring the effectiveness of the therapy and detecting the return of undesirable microorganisms.

Bacteria↗
PubMedDate not supplied

The role of Bacteroides melaninogenicus and other anaerobes in periodontal infections.

Recent taxonomic and anatomical studies of dental plaque associated with periodontal health and disease have demonstrated that differences in the microbial populations in plaque may be responsible for the initiation and progression of disease. The consistent isolation of large numbers of anaerobic and capnophilic bacteria from the depths of periodontal lesions has suggested an important role for these organisms. Bacteria that have been isolated include Capnocytophaga (Bacteroides ochraceus), other species of Bacteroides, Fusobacterium, Selenomonas, spirochetes, Campylobacter, Veillonella, Actinomyces, Propionibacterium, Peptococcus, and other genera. The periodontopathic potential of oral strains of Bacteroides melaninogenicus has been explored in a number of investigations because these organisms are consistently isolated from periodontal lesions. Studies of B. melaninogenicus have included purification of a capsular substance, characterization of the lipopolysaccharide and a variety of toxic substances and lytic enzymes, and ecologic aspects of its colonization. Understanding of the nature and pathogenic mechanisms of the oral microbiota may lead to control of this pandemic infection.

Bacteroides Infections↗
PubMed1979

Transoral removal of a fractured odontoid process.

The indications for an anterior approach are lesions located predominantly in the body of the vertebra or intervertebral disks. Among these are spondylolisthesis, tuberculosis of the spine, prolapsed intervertebral disks, neoplasms, spinal biopsies, correction of fixed spinal curves, fractures, and fracture dislocations of the spine. Despite many indications, this approach is rarely used, primarily because of unfamiliarity with the surgical field, instrumentation, and oral microbiota. Use of appropriate disciplines and consultations enabled this patient to receive comprehensive treatment from a community of health care specialists.

Cervical Vertebrae↗
PubMed1977

International aspects of oral microbiology.

It appears that the bacteria of the mouth are remarkably similar throughout the world. There are differences, but they are mostly of a quantitative rather than a qualitative nature. Although much is yet to be learned on the regulation of the oral ecosystems, these quantitative fluctuations to a large extent seem to be induced by different dietary patterns: the food exerting a strong selective pressure on the oral microbiota.

Bacteria↗
PubMed2026

Association Between cnm-Positive Streptococci and Cerebral Small Vessel Disease: Insights From Oral Health and Microbiome Status.

INTRODUCTION AND AIMS: Cerebral small vessel disease (CSVD) is associated with various severe neurological outcomes; while oral cnm-positive streptococci are suggested to be involved in cerebrovascular lesions, the specific associative features between these bacteria and CSVD have not yet been systematically investigated. This study aims to investigate the prevalence of cnm-positive streptococci in patients with CSVD and explore the correlation between infection and CSVD severity. By integrating oral health indices and microbiome sequencing, we evaluate the oral hygiene status and microbial dysbiosis characteristics of cnm-positive streptococci carriers. Furthermore, cnm-positive streptococci derived from CSVD patients will be isolated, identified, and subjected to whole-genome sequencing to provide a foundation for future research. METHODS: To explore cnm-positive streptococci prevalence and its association with CSVD, we conducted a case-control study comparing their oral detection rates between healthy controls and CSVD patients. We also performed 16S rRNA gene high-throughput sequencing of oral plaque microbiota and assessed oral health, including the simplified oral hygiene index (OHI-S), the decayed, missing, and filled teeth (DMFT) index, oral hygiene practices, gingival status, and saliva scores. RESULTS: cnm-positive streptococci were more prevalent in CSVD patients, correlating with higher OHI-S and microbial dysbiosis. Multivariable regression models (adjusted for demographic/vascular risk factors) linked cnm positivity to periventricular hyperintensities (PVH), deep white matter hyperintensities (DWMH), Fazekas score, and total CSVD burden (not cerebral microbleeds (CMBs)/lacunes). CONCLUSION: Oral cnm-positive streptococci are independently associated with CSVD phenotypes, particularly those characterized by white matter injury. These findings presents a potential oral-cerebrovascular interaction and imply that managing specific virulent oral strains may be a noteworthy consideration in future clinical research.

Humans↗
PubMed2026

Causal relationships between oral-gut microbiome and bone neoplasm-related phenotypes: Insights from bidirectional Mendelian randomization.

The human oral and gut microbiota are the 4 largest microbial communities in the body and play crucial roles in maintaining homeostasis and influencing disease. Observational studies have suggested links between these microbiota and bone neoplasm-related phenotypes, but establishing causality has been challenging due to confounding factors and reverse causality. We conducted a bidirectional, 2-sample Mendelian randomization (MR) study to investigate evidence consistent with a potential causal association between the saliva and gut microbiota and various bone neoplasm-related phenotypes. Genetic instruments for saliva and gut microbiota were sourced from large genome-wide association studies. Inverse variance weighted was the primary MR method, supplemented by 4 other MR techniques. Sensitivity analyses, including MR-Egger regression, were performed to assess pleiotropy and heterogeneity. In the forward MR analysis, Veillonella parvula from the saliva microbiota was associated with a decreased risk of bone and connective tissue neoplasms (β: -0.236, 95% CI: [-0.275, -0.197], P = 8.20E-33). MR analyses identified genetically predicted associations between several microbial taxa and bone neoplasm-related phenotypes. Reverse MR analyses showed that genetic liability to bone neoplasm-related phenotypes was associated with variation in the composition of the oral (e.g., Order Bacteroidales, Rothia mucilaginosa) and gut microbiota (e.g., Class Methanobacteria, Genus Eubacterium oxidoreducens group). Sensitivity analyses confirmed the robustness of these findings, as no statistical evidence of substantial heterogeneity or directional horizontal pleiotropy was detected. This study provides genetic evidence supporting a bidirectional causal relationship between specific saliva and gut microbiota and bone neoplasm-related phenotypes. Our findings identify several microbial taxa as potential candidates for future biomarker development and therapeutic investigation in bone neoplasm-related phenotypes. However, these genetically informed associations require further mechanistic, experimental, and prospective clinical validation before clinical application.

Humans↗
PubMed2025

Integrative oral and gut microbiome profiling highlights microbial correlates of complications in type 1 diabetes: a cross-sectional analysis.

BACKGROUND/OBJECTIVE: Chronic vascular complications are the primary threat in long-standing type 1 diabetes (T1D) patients. We examined the associations between oral-gut microbiome dysbiosis and these complications, offering novel insights into therapeutic strategies and underlying mechanisms. METHODS: This cross-sectional study enrolled 75 T1D participants (disease duration ≥ 10 years) and 43 healthy controls who underwent comprehensive clinical assessment, including blood glucose, lipid profile, and complication-related examinations. Fecal and oral rinse samples were collected for shotgun metagenomic sequencing. T1D participants were stratified by the presence of microvascular (retinopathy, nephropathy, or neuropathy) or macrovascular complications separately. Microbial differences across groups were assessed. RESULTS: Significant differences in oral and gut microbiota compositions were observed between T1D participants with and without complications (both microvascular and macrovascular). A core set of 26 gut and 8 oral microbial species was specifically associated with vascular complications. Butyrate-producing gut bacteria (Blautia wexlerae, Anaerobutyricum hallii, Roseburia inulinivorans, A. soehngenii) and specific oral Neisseria species were enriched in T1D without complications individuals, suggesting protective effects against complications. Mediation analysis indicated associations consistent with partial mediation between certain microbial species and the relationships of glycemic control or insulin resistance (HbA1c, glucose risk index, estimated glucose disposal rate) with complication risk. Moreover, potential oral-gut microbiome interconnections were implicated in complication development. Finally, classification models integrating both oral and gut microbial features significantly outperformed models based on either site alone in distinguishing T1D patients with complications. CONCLUSIONS: Distinct oral and gut microbiome features are associated with chronic vascular complications in T1D. These findings highlight the potential of microbiome-targeted strategies for understanding and preventing T1D-related complications.

Humans↗
PubMed2025

Microbial signals in primary and metastatic brain tumors.

Gliomas and brain metastases are associated with poor prognosis, necessitating a deeper understanding of brain tumor biology and the development of effective therapeutic strategies. Although our group and others have demonstrated microbial presence in various tumors, recent controversies regarding cancer-type-specific intratumoral microbiota emphasize the importance of rigorous, orthogonal validation. This prospective, multi-institutional study included a total of 243 samples from 221 patients, comprising 168 glioma and brain metastases samples and 75 non-cancerous or tumor-adjacent tissues. Using stringent fluorescence in situ hybridization, immunohistochemistry and high-resolution spatial imaging, we detected intracellular bacterial 16S rRNA and lipopolysaccharides in both glioma and brain metastases samples, localized to tumor, immune and stromal cells. Custom 16S and metagenomic sequencing workflows identified taxa associated with intratumoral bacterial signals in the tumor microenvironment; however, standard culture methods did not yield readily cultivable microbiota. Spatial analyses revealed significant correlations between bacterial 16S signals and antimicrobial and immunometabolic signatures at regional, neighborhood and cellular levels. Furthermore, intratumoral 16S bacterial signals showed sequence overlap with matched oral and gut microbiota, suggesting a possible connection with distant communities. Together, these findings introduce microbial elements as a component of the brain tumor microenvironment and lay the foundation for future mechanistic and translational studies.

Humans↗