Microbiota-based Signature of Gingivitis Treatments: A Randomized Study

Association between dental floss use and atherosclerotic cardiovascular disease in American adults

BACKGROUND

Atherosclerotic cardiovascular disease (ASCVD) remains a major cause of global morbidity and mortality. Emerging research suggests that oral hygiene practices, particularly dental floss use, may reduce the risk of ASCVD.

OBJECTIVES

The purpose of this study was to examine the association between dental floss use and ASCVD prevalence.

METHODS

Data from NHANES participants who completed home interviews and dental evaluations were analyzed. ASCVD was defined as angina, stroke, myocardial infarction, or coronary artery disease. Dental floss use was self-reported over the past seven days. Covariates included demographic, socioeconomic, lifestyle, and clinical factors. Weighted logistic regression was used to assess the relationship between dental floss use and ASCVD prevalence.

RESULTS

This study included a total sample of 7253 participants with a mean age of 53.8±14.6 years. The sample consisted of 47.6 % male participants. The ethnic composition included 64.3 % Non-Hispanic White. Regular dental floss use was correlated with a lower likelihood of developing ASCVD and Stringent Criteria (infarction or stroke), with ORs of 0.76 (95 % CI: 0.60, 0.97) p=0.028 and 0.68 (95 % CI: 0.49, 0.94) p=0.022, respectively. Flossing 3-4 days/week was associated with reduced ASCVD risk, OR = 0.57 (95 % CI: 0.38, 0.84) p=0.006. Similar reductions were seen for stringent criteria: flossing 3-4 days/week: OR = 0.57 (95 % CI: 0.32, 0.99) p=0.047, flossing ≥5 days/week: OR = 0.69 (95 % CI: 0.47, 1.00) p=0.049.

CONCLUSIONS

Regular dental floss use may reduce the risk of ASCVD. These results support the inclusion of oral hygiene practices in cardiovascular disease prevention strategies.

Persisting Chronic Periodontal Disease as a Risk Factor for Cardiovascular Disease: A Nationwide Population-Based Cohort Study

AIMS

Epidemiological studies have consistently established a positive association between periodontal disease (PD) and cardiovascular disease (CVD). However, large-scale investigations exploring the impact of changes in PD status on CVD risk are scarce. This study aimed to investigate the association between the dynamics in PD and the risk of incident CVD in a nationally representative population.

METHODS

Utilising data from the Korean National Health Insurance Service, a cohort of 1,242,570 participants who underwent oral health exams in 2003 and a follow-up exam in 2005-2006 was analysed. Participants were categorized into groups based on changes in PD status: absent, improvement, onset and persistent. Cox proportional hazard models were employed to assess the multivariate-adjusted hazard ratios (HRs) for composite CVD outcomes, including death, myocardial infarction and stroke.

RESULTS

Over a mean follow-up of 14.4 years, 79,810 (6.4%) cases of composite CVD occurred, including 14,296 (1.2%) myocardial infarctions, 3247 (0.3%) hemorrhagic strokes and 8900 (0.7%) ischemic strokes. Individuals with persistent PD showed the highest risk of CVD (HR: 1.04, 95% CI: 1.03-1.06, p < 0.001). In the pairwise comparisons, the PD improvement group exhibited a lower composite CVD risk than the PD persistent group (HR: 0.97, 95% CI: 0.96-0.99, p = 0.010); similarly, the PD onset group showed a lower risk than the PD persistent group (HR: 0.94, 95% CI: 0.93-0.96, p < 0.001). This pattern was consistent in the risk of death, with both the PD improvement and PD onset groups showing a lower risk of death than the PD persistent group.

CONCLUSION

This study suggests the dynamic nature of PD as a potential modifiable risk factor for CVD. Individuals with chronically persistent PD showed an elevated incidence risk of CVD, emphasizing the importance of managing PD in preventive strategies.

Salivary microbiome profile shifts after scaling in stunted children

OBJECTIVE

Stunting is a condition of impaired growth in children resulting from chronic malnutrition, characterized by shorter stature compared to peers of the same age. This condition leads to salivary gland dysfunction, which triggers oral dysbiosis and increases the risk of periodontal disease in children. Scaling and root planing (SRP) is the gold standard treatment for periodontal disease, aimed at reducing pathogenic bacterial populations. This study aimed to evaluate the effect of SRP treatment on the oral microbiome profile in the saliva of stunted children. A pre- and post-test study design was employed, involving 10 elementary school children divided into two groups: normal children and stunted children. Each participant underwent scaling, with saliva samples collected before and after the procedure. The oral microbiome profile was analyzed using next-generation sequencing, generating taxonomic data at the phylum, genus, and species level.

RESULT

Statistical analysis revealed significant changes in the gingival index, a clinical parameter, in the normal group but not in the stunted group. Scaling resulted in shifts in the microbiome profile in both groups, with the dominant phyla identified as Proteobacteria, Bacteroidota, and Firmicutes. Scaling procedure alters the oral microbiome profile in stunted children without affecting the clinical parameter.

Effects of Antimicrobial Agents Used for Dental Treatments: Impacts on the Human Oral Ecosystem and the Resistome

Antimicrobial resistance (AMR) is a major public health concern, especially with regard to bacterial resistance to antibiotics. Dentists are responsible for approximately 10% of all antibiotic prescriptions. In addition, there seems to be a lack of awareness of potential resistance toward antiseptics and biocides such as chlorhexidine digluconate (CHX) or cetylpyridinium chloride (CPC), which are commonly used in dental practice but also included in over-the-counter products. In comparison to the gut microbiome, only a small number of studies have investigated the impact of antibiotics on the oral microbiome. Amoxicillin is a commonly prescribed antibiotic in dentistry, often used in combination with metronidazole. Several studies have addressed its impact on the oral microbiome. Similarly, the effects of ciprofloxacin, clindamycin, cephazolin, and benzylpenicillin have also been examined in various studies. However, due to variations in study designs, it is difficult to compare the effects of antibiotics on the oral microbiota, and conclusions can only be drawn at the phyla level. In contrast, studies on CPC and CHX have also focused on the genus level. The oral resistome mainly contains genes involved in resistance to macrolides, MLSB (macrolide, lincosamide, and streptogramin B), lincosamide and streptogramin A, fluoroquinolone, tetracycline, or penicillin. The oral cavity therefore serves as a reservoir for antibiotic resistance genes (ARGs), which are of crucial importance both for inflammations in the oral cavity and for the treatment of the entire human organism. Therefore, dentists must weigh up the benefits and risks of using antibiotics very carefully.

Microbiological profile of patients with generalized gingivitis undergoing periodontal therapy and administration of Bifidobacterium animalis subsp. lactis HN019: A randomized clinical trial

OBJECTIVE

To evaluate the adjunctive use of the probiotic Bifidobacterium animalis subsp. lactis HN019 (B. lactis HN019) to conventional therapy on clinical and microbiological parameters in patients with generalized gingivitis.

METHODS

Sixty systemically healthy individuals with untreated generalized gingivitis were submitted to periodontal therapy and allocated to receive Placebo (n = 30) or Probiotic (n = 30) lozenges, twice a day for 8 weeks. Bleeding on Marginal Probing (BOMP) was evaluated at baseline, after 2 and 8 weeks. Supra and subgingival biofilm were obtained at baseline and 8 weeks post-therapy for analyses by 16S rRNA gene sequencing. Differences between therapeutic groups were analyzed by non-parametric tests (p<0.05).

RESULTS

The Placebo and Probiotic groups showed a significant reduction in BOMP at 8 weeks compared to baseline (p<0.05). The Probiotic group had a lower percentage of BOMP when compared with the Placebo group at 8 weeks (p<0.0001). Alpha and beta-diversity showed no statistical significance between groups and time points. At phylum level, no significant differences were observed between groups and time points. At genus level, an increase in the relative abundances of Bergeyella and Corynebacterium were significantly associated with a greater reduction in bleeding in the Placebo group and with less reduction in bleeding in the Probiotic group, respectively. At species level, Schaalia spp., Streptococcus gordonii, and Leptotrichia wadei increased in Placebo and decreased in the Probiotic group after treatment. Granulicatella adiacens decreased significantly after the probiotic therapy, while Saccharibacteria (TM7) spp., Solobacterium moorei, and Catonella morbi increased significantly. In the Placebo group, Bergeyella sp. HMT-322 was associated with a greater percentage of reduction in bleeding. In both groups, Actinomyces species were related to less reduction in bleeding.

CONCLUSION

The adjuvant use of B. lactis HN019 alongside conventional therapy enhanced the reduction in BOMP and promoted greater changes in the microbiological profile of patients with generalized gingivitis.

TRIAL REGISTRATION

The study was registered at Brazilian Clinical Trials Registry (ReBEC; protocol number: RBR-59v2yb).

Chronic periodontal disease is related with newly developing hypertension: a nationwide cohort study

BACKGROUND

Periodontal disease (PD) is a condition that can be treated and managed. This study aimed to determine if chronic PD status is associated with the risk of developing hypertension, utilizing data from the National Health Insurance Database of Korea.

METHODS

Participants who received oral health examinations both in 2003 and in 2005-2006 were included. Those with a history of hypertension were excluded. Hypertension was defined as at least one outpatient or inpatient claim diagnosis (primary or secondary) of hypertension (International Classification of Diseases (ICD)-10 codes I10-I11) with prescription for antihypertensive medication or at least one incident of systolic blood pressure greater than 140 mmHg or diastolic blood pressure greater than 90 mmHg during a health examination. Changes of PD status was determined during two oral examinations. Study participants were divided into 4 groups according to the changes of PD status: PD-free (those consistently free of disease in both exams), PD-recovered (individuals with disease initially but not in the second exam), PD-developed (no disease initially, but present in the second exam), and PD-chronic (disease throughout both exams). The incidence of hypertension after the second oral health examination (index date) was monitored. Participants were observed from the index date until the earliest occurrence of hypertension onset, mortality, or December 2020.

RESULTS

The study comprised 706,584 participants: 253,003(35.8%) in the PD-free group, 140,143(19.8%) in the PD-recovered group, 132,397(18.7%) in the PD-developed group, and 181,041(25.6%) in the PD-chronic group. Over a median follow-up duration of 14.3 years, 239,937 (34.0%) cases of hypertension were recorded. The PD-recovered group had a lower risk of hypertension compared to the PD-chronic group, while the PD-developed group had a higher risk of hypertension compared to the PD-free group.

CONCLUSION

Chronic PD is associated with an increased risk of developing hypertension. Although the increase in risk is modest, recovery from PD may have beneficial effects in reducing hypertension risk. Further studies are needed to confirm the importance of regular dental examinations and effective management of PD to reduce hypertension risk.

Microbiological and functional traits of peri-implant mucositis and correlation with disease severity

Osseointegrated dental implants replace missing teeth and create an artificial surface for biofilms of complex microbial communities to grow. These biofilms on implants and dental surfaces can trigger infection and inflammation in the surrounding tissue. This study investigated the microbial characteristics of peri-implant mucositis (PM) and explored the correlation between microbial ecological imbalance, community function, and disease severity by comparing the submucosal microflora from PM with those of healthy inter-subject implants and intra-subject gingivitis (G) within a group of 32 individuals. We analyzed submucosal plaques from PM, healthy implant (HI), and G sites using metagenome shotgun sequencing. The bacterial diversity of HIs was higher than that of PM, according to the Simpson index. Beta diversity revealed differences in taxonomic and functional compositions across the groups. Linear discriminant analysis of the effect size identified 15 genera and 37 species as biomarkers that distinguished PM from HIs. Pathways involving cell motility and protein processing in the endoplasmic reticulum were upregulated in PM, while pathways related to the metabolism of cofactors and vitamins were downregulated. Microbial dysbiosis correlated positively with the severity of clinical inflammation measured by the sulcus bleeding index (SBI) in PM. Prevotella and protein processing in the endoplasmic reticulum also correlated positively with the SBI. Our study revealed PM's microbiological and functional traits and suggested the importance of certain functions in disease severity.IMPORTANCEPeri-implant mucositis is an early stage in the progression of peri-implantitis. The high prevalence of it has been a threat to the widespread use of implant prosthodontics. The link between the submucosal microbiome and peri-implant mucositis was demonstrated previously. Nevertheless, the taxonomic and functional composition of the peri-implant mucositis microbiome remains controversial. In this study, we comprehensively characterize the microbial signature of peri-implant mucositis and for the first time, we investigate the correlations between microbial dysbiosis, functional potential, and disease severity. With the help of metagenomic sequencing, we find the positive correlations between microbial dysbiosis, genus Prevotella, pathway of protein processing in the endoplasmic reticulum, and more severe mucosal bleeding in the peri-implant mucositis. Our studies offer insight into the pathogenesis of peri-implant mucositis by providing information on the relationships between community function and disease severity.

Supra- and Subgingival Microbiome in Gingivitis and Impact of Biofilm Control: A Comprehensive Review

This comprehensive review aimed (1) to characterize the sub- and supragingival microbiome in patients with biofilm-induced gingivitis (including experimental gingivitis), (2) to assess its stability and evolution over time, and (3) to assess the impact of biofilm control measures on this stability. An electronic search of the MEDLINE®/PubMed® database until December 2023 was conducted. NCBI Taxonomy, eHOMD 16S rRNA Reference Sequence, and Tree Version 15.23 databases were used to standardize taxonomic nomenclature. Out of 89 papers initially retrieved, 14 studies were finally included: 11 using experimental gingivitis as a model and three randomized clinical trials evaluating the impact of biofilm control measures. Among them, five characterized the subgingival microbiome, nine the supragingival microbiome, and one both the sub- and supragingival microbiome. In addition, five studies evaluated the effect of toothpaste, and four studies evaluated the effect of mouth rinses. The diversity and structure of the microbiome differed significantly between patients with periodontal health and those with biofilm-induced gingivitis (including experimental gingivitis). Those differences were not reversed through conventional oral hygiene measures. Specific antiseptic agents, especially if delivered as mouth rinses, may have an impact on the supra- and subgingival microbiome in gingivitis.

Subgingival microbial changes in Down Syndrome adults with periodontitis after chlorhexidine adjunct non-surgical therapy and monthly recalls-A 12-month case series study

OBJECTIVES

Down Syndrome (DS) adults are at risk for periodontitis. Previous reports indicated difficulties in periodontopathogen reduction or eradication in DS individuals after periodontal treatment. This case series follows the subgingival microbial changes in adult DS individuals with periodontitis who received chlorhexidine adjunct non-surgical therapy plus 12-month recalls.

METHODS

Twenty periodontitis DS participants (7 females; 25.5 ± 5.6 years of age; 3 with generalized periodontitis) partook in a study involving non-surgical mechanical periodontal therapy, twice daily chlorhexidine gel toothbrushing, chlorhexidine mouthwash, and monthly recalls. The subgingival microbiota profile was followed at baseline, 6-, and 12-months post-operation.

RESULTS

Desulfobulbus, Saccharibacteria (TM7), Tannerella, and Porphyromonas were the major subgingival genera in this DS cohort. Favorable chlorhexidine adjunct non-surgical treatment outcomes were observed, with the relative abundance of Desulfobulbus sp. HMT 041, Saccharibacteria (TM7) [G-1] bacterium HMT 346 or 349, and Tannerella forsythia significantly reduced at the end of the study, but no significant reduction of Porphyromonas gingivalis or Aggregatibacter actinomycetemcomitans could be observed. Relative abundance of Desulfobulbus sp. HMT 041 and T. forsythia were also found to be significantly associated with plaque, bleeding on probing, and probing pocket depth (PPD, in mm) at a site level, while the relative abundance of Halomonas pacifica was negatively associated with PPD.

CONCLUSIONS

Successful chlorhexidine adjunct non-surgical treatment with hygiene care was accompanied by a subgingival microbial shift involving certain periodontopathogenic species, except P. gingivalis and A. actinomycetemcomitans. Further investigations are required to clarify the mechanism underpinning the unchanged relative abundance of the above two pathogens despite favorable clinical responses.

CLINICAL SIGNIFICANCE

DS adults face challenges achieving optimal home care or hygiene for periodontal healing and disease prevention. Chemical adjunct mechanical periodontal therapy plus regular recalls appeared promising clinically and microbiologically, with subgingival periodontopathogenic species reduction. The persistence of A. actinomycetemcomitans and P. gingivalis in subgingival niches post-treatment warrants further investigation.

Shotgun metagenomic analysis of the oral microbiome in gingivitis: a nested case-control study

Background

Gingivitis, i.e. inflammation of the gums, is often induced by dentalplaque. However, its exact link to the oral microbiota remains unclear.

Methods

In a case-control study involving 120 participants, comprising 60 cases and 60 controls (mean age (SD) 36.6 (7.6) years; 50% males), nested within a prospective multicentre cohort study, we examined theoral microbiome composition of gingivitis patients and their controlsusing shotgun metagenomic sequencing of saliva samples. Participants underwent clinical and radiographic oral health examinations, including bleeding on probing (BOP), at six tooth sites. BOP ≥33%was considered 'generalized gingivitis/initial periodontitis'(GG/IP), and BOP <33% as 'healthy and localized gingivitis'(H/LG). Functional potential was inferred using HUMANn3.

Results

GG/IP exhibited an increase in the abundance of Actinomyces, Porphyromonas, Aggregatibacter, Corynebacterium, Olsenella, and Treponema, whereas H/LG exhibited an increased abundance of Candidatus Nanosynbacter. Nineteen bacterial species and fourmicrobial functional profiles, including L-methionine, glycogen, andinosine-5'-phosphate biosynthesis, were associated with GG/IP. Constructing models with multiple markers resulted in a strong predictive value for GG/IP, with an area under the curve (ROC) of 0.907 (95% CI: 0.848-0.966).

Conclusion

We observed distinct differences in the oral microbiome between the GG/IP and H/LG groups, indicating similar yet unique microbial profiles and emphasizing their potential role in progression of periodontal diseases.

Association of Dental Diseases and Oral Hygiene Care With the Risk of Heart Failure in Patients With Type 2 Diabetes: A Nationwide Cohort Study

Background To evaluate the association of dental diseases and oral hygiene care with incidence of heart failure (HF) among patients with type 2 diabetes. Methods and Results This study included 173 927 patients with type 2 diabetes aged ≥40 years, who underwent Korean National Health Insurance Service health examinations in 2008 and were followed up until the end of 2017. Hazard ratios (HRs) and 95% CIs for HF were estimated using multivariable Cox proportional hazards regression analysis. During a median follow-up of 9.3 years, 1.94% of participants developed HF. An increased number of missing teeth was associated with a higher risk of HF (P<0.001). HRs of HF increased among individuals with ≥15 missing teeth (HR, 1.37 [95% CI, 1.14-1.64]) compared with those without missing teeth. Decreased risk of HF was observed in individuals with ≥1 time/year of professional dental cleaning (HR, 0.93 [95% CI, 0.87-0.99]) and in those with ≥2 times/d of toothbrushing (HR, 0.90 [95% CI, 0.82-0.98]) compared with those without these practices. While combined presence of missing teeth and periodontal disease (P=0.004) or dental caries (P=0.007) increased HF risk, combined oral hygiene care was associated with further HF risk reduction (P=0.024). Better oral hygiene care was associated with decreased HF risk, even as the number of missing teeth increased (P<0.001). Conclusions Among patients with type 2 diabetes, dental diseases and oral hygiene care are important determinants of HF development. Dental disease management and good oral care may prevent HF in patients with type 2 diabetes.

Association between periodontal disease status and risk of atrial fibrillation: a nationwide population-based cohort study

BACKGROUND

Periodontal disease can activate an immune process linked to systemic diseases, including atrial fibrillation. However, the relationship between periodontal disease and atrial fibrillation remains unclear.

AIM

This study aimed to investigate whether changes in periodontal disease status are associated with the risk of atrial fibrillation.

METHODS

Using the National Health Insurance Database Korea, participants who underwent the first oral health examination in 2003 and a second examination in 2005-2006 without a history of atrial fibrillation were included. Participants were grouped according to changes in periodontal disease status during two oral examinations: periodontal disease-free, periodontal disease-recovered, periodontal disease-developed, and periodontal disease-chronic. The outcome was the incidence of atrial fibrillation.

RESULTS

The study included 1,254,515 participants, with a median follow-up of 14.3 years and 25,402 (2.02%) cases of atrial fibrillation occurred. During follow-up, the risk of atrial fibrillation was highest in the periodontal disease-chronic group, followed by the periodontal disease-developed, periodontal disease-recovered, and periodontal disease-free groups (p for trend < 0.001). Moreover, recovery from periodontal disease was associated with a reduced risk of atrial fibrillation compared to a chronic periodontal disease status (Hazard ratio: 0.97, 95% Confidence interval: 0.94-0.99, p = 0.045). The development of periodontal disease was associated with an increased risk of atrial fibrillation compared to being periodontal disease-free (Hazard ratio: 1.04, 95% Confidence interval: 1.01-1.08, p = 0.035).

CONCLUSION

Our findings suggest that changes in periodontal disease status impact the risk of atrial fibrillation. Management of periodontal disease may help prevent atrial fibrillation.

Construction of a caries diagnosis model based on microbiome novelty score

OBJECTIVES

This study aimed to analyze the bacteria in dental caries and establish an optimized dental-ca-ries diagnosis model based on 16S ribosomal RNA (rRNA) data of oral flora.

METHODS

We searched the public databa-ses of microbiomes including NCBI, MG-RAST, EMBL-EBI, and QIITA and collected data involved in the relevant research on human oral microbiomes worldwide. The samples in the caries dataset (1 703) were compared with healthy ones (20 540) by using the microbial search engine (MSE) to obtain the microbiome novelty score (MNS) and construct a caries diagnosis model based on this index. Nonparametric multivariate ANOVA was used to analyze and compare the impact of different host factors on the oral flora MNS, and the model was optimized by controlling related factors. Finally, the effect of the model was evaluated by receiver operating characteristic (ROC) curve analysis.

RESULTS

1) The oral microbiota distribution obviously differed among people with various oral-health statuses, and the species richness and species diversity index decreased. 2) ROC curve was used to evaluate the caries data set, and the area under ROC curve was AUC=0.67. 3) Among the five hosts' factors including caries status, country, age, decayed missing filled tooth (DMFT) indices, and sampling site displayed the strongest effect on MNS of samples (P=0.001). 4) The AUC of the model was 0.87, 0.74, 0.74, and 0.75 in high caries, medium caries, low caries samples in Chinese children, and mixed dental plaque samples after controlling host factors, respectively.

CONCLUSIONS

The model based on the analysis of 16S rRNA data of oral flora had good diagnostic efficiency.

Effects of antimicrobial mouthwashes on the human oral microbiome: Systematic review of controlled clinical trials

OBJECTIVES

This review aimed to assess the impact of mouthwashes on the composition of the human oral microbiome.

METHOD

An electronic search algorithm was adapted to MEDLINE-PubMed, Scopus, Embase and ISI Web of Science, and reference lists of relevant sources were manually searched. Inclusion criteria were controlled clinical trials published in English whose population were adult individuals who rinse with antimicrobial mouthwashes and that analysed changes in the oral microbiome by metataxonomy, metagenomics or phylogenetic microarray. Identified studies were screened and assessed following the PRISMA guidelines, and results were compiled into qualitative synthesis of the evidence.

RESULTS

Five controlled clinical studies were included. These studies found associations between the daily use of mouthwashes and changes in the oral microbiome, but the nature of the effect varied according to the mouthwash. Chlorhexidine (CHX) rinses lowered microbial diversity. While 7-day use of CHX led to increases in the abundance of Neisseria, Streptococcus and Granulicatella and a decrease in the abundance of Actinomyces, its prolonged use led to widespread reductions in several genera and species. Cetylpyridinium chloride-containing mouthwashes specifically lowered the abundance of gingivitis-associated genera. In contrast, N-acetyl cysteine-based mouthwashes did not promote changes in the oral microbiome.

CONCLUSIONS

Despite substantial heterogeneity, we found evidence to support the hypothesis that CHX and CPC mouthwashes promote changes in oral microbial structure and/or reductions in community diversity that favour the resolution of dysbiosis. However, future large population-based studies of adequate duration are needed to fully understand the extent to which antimicrobial mouthwashes modulate the microbiome.

Better Oral Hygiene Is Associated with a Decreased Risk of Meniere's Disease: A Nationwide Cohort Study

To investigate the association of the oral health parameters with Meniere’s disease in a nationwide population-based longitudinal cohort database. The data of the participants who underwent an oral health screening by dentists in 2003 (n = 2,415,963) were retrieved from the National Health Insurance Database of the Korean National Health Insurance Service. The main outcome was the occurrence of Meniere’s disease, defined as two or more claims of the diagnostic code H810 with a previous audiometric examination. The occurrence of Meniere’s disease was analyzed using a Cox proportional hazard model according to the presence of periodontitis and the oral health examination findings, including missing teeth, the frequency of tooth brushing and dental scaling. Overall, the analysis included 2,240,282 participants. During a median follow-up of 16.7 years, Meniere’s disease developed in 112,106 (5.0%) participants. Poor oral health status was characterized by the presence of periodontitis (adjusted hazard ratio [aHR]: 1.18, 95% confidence interval [CI]: 1.14−1.22, p < 0.001) and an increased number of missing teeth (≥15; aHR: 1.25, 95% CI: 1.18−1.32, p < 0.001) was associated with an increased risk of Meniere’s disease. Better oral hygiene behaviors, such as frequent tooth brushing (≥3 per day; aHR: 0.75, 95% CI: 0.73−0.76, p < 0.001) and dental scaling within 1 year (aHR: 0.98, 95% CI: 0.97−0.99, p = 0.003) were negatively associated with the occurrence of Meniere’s disease. The presence of periodontitis and an increased number of missing teeth may augment the risk of the occurrence of Meniere’s disease. However, maintaining good oral hygiene through tooth brushing and dental scaling may be associated with a decreased risk of Meniere’s disease. Further studies should confirm the association between oral health and Meniere’s disease.

Improved Oral Health Status Is Associated with a Lower Risk of Venous Thromboembolism: A Nationwide Cohort Study

Oral health is reportedly associated with several systemic diseases, particularly cardiovascular diseases, through systemic inflammatory and thrombotic mechanisms. This study aimed to investigate the association between oral health status, oral hygiene behavior, and venous thromboembolism (VTE) in a nationwide, population-based cohort database in a longitudinal setting. Data of participants who underwent oral health screening by dentists between January and December 2003 (n = 2,415,963) were retrieved from the National Health Insurance Database of the Korean National Health Insurance Service. Periodontitis was identified using claims or oral health screening data. Periodontal pockets and the number of missing teeth were examined by dentists during oral health screenings. Data on oral hygiene behaviors (tooth brushing, dental visits, and dental scaling) were collected. VTE was defined as two or more claims of one of the following ICD-10 codes: deep (I80.2−80.3), pulmonary (I26, I26.0, I26.9), intra-abdominal (I81, I82, I82.2, I82.3), and other (I82.8, I82.9) VTE and concurrent medication (anticoagulants and antiplatelets). VTE was analyzed using the Cox proportional hazard model according to periodontitis, number of missing teeth, tooth brushing frequency, dental visits, and dental scaling. VTE occurred in 39,851 (1.8%) participants within a median of 17.0 (interquartile range 16.3−17.7) years. Periodontitis was associated with VTE (adjusted hazard ratio (HR), 1.2; 95% confidence interval (CI), 1.15−1.28; p < 0.001). An increased number of missing teeth was associated with an increased risk of VTE; the adjusted HR (versus participants without missing teeth) was 1.58 (95% CI, 1.46−1.71; p < 0.001, p for trend < 0.001) for participants with ≥15 missing teeth. Furthermore, tooth brushing ≥3 times a day was negatively correlated with VTE (adjusted HR, 0.67; 95% CI, 0.65−0.69; p < 0.001, p for trend < 0.001). Dental scaling within one year was associated with a significantly lower risk of VTE (adjusted HR, 0.95; 95% CI, 0.93−0.98; p < 0.001). Improved oral hygiene, including tooth brushing and dental scaling, may be associated with a decreased risk of VTE. Periodontitis and an increased number of missing teeth may increase the risk of VTE.

Effect of Periodontal Interventions on Characteristics of the Periodontal Microbial Profile: A Systematic Review and Meta-Analysis

Our systematic review aimed to evaluate the effect of periodontal interventions on the diversity and composition of periodontal microbiota assessed by high throughput sequencing (HTS) metagenomics analysis. An electronic search was conducted from database inception to November 2021. All clinical trials that evaluated the effect of periodontal interventions on the gingival microbiota through HTS were selected. The measures of alpha diversity, richness, Shannon diversity index, and the Chao1 index, were used as the primary outcome, whereas relative abundances of bacterial genera were considered as the secondary outcome. Overall, 24 studies were eligible for the systematic review, of which 13 studies were included in the meta-analysis. Periodontal intervention for the test group decreased Shannon diversity, richness, and Chao1 index (alpha diversity), as observed from baseline to post-treatment. The most common genera that increased after periodontal therapy were Rothia, Actinomyces, Streptococcus, Veillonella, and Hemophilus, whilst Porphyromonas, Tannerella, Fusobacterium, and Treponema decreased after periodontal therapy. Periodontal interventions may decrease the bacterial diversity and richness and alter the composition of oral microbiota in the short term. Periodontal microbiota signatures could potentially be used for the assessment of periodontal disease development, progression, and success of the intervention.

Oral Health, Antimicrobials and Care for Patients With Chronic Oral Diseases – A Review of Knowledge and Treatment Strategies

Periodontal and chronic oral mucosal diseases are significant life impacting conditions which may co-exist and synergistically act to cause more severe and widespread oral pathology with enhanced challenges in effective management. Clinicians regularly observe these effects and struggle to effectively manage both problems in many patients. There is limited understanding of many basic and applied scientific elements underpinning potentially shared aetiopathological features and management. Recent developments in translational science provide an opportunity to greater improve knowledge and subsequently care for patients with these problems.

Profile of the oral microbiota from preconception to the third trimester of pregnancy and its association with oral hygiene practices

Background

The oral microbiota plays vital roles in both oral and systemic health, but limited studies have explored the transition of the female oral microbiota from preconception to pregnancy along with pronounced hormonal fluctuations.

Aim

To characterize the oral microbiota among women in preconception and pregnancy through a prospective study and to explore the associations between the oral microbiota and oral hygiene practices.

Methods

A total of 202 unstimulated saliva samples were collected from 101 women in both preconception and late pregnancy. The oral microbiota was analyzed using 16S rRNA gene sequencing.

Results

The Ace and phylogenetic diversity (PD) index were significantly lower in the third trimester than preconception. The pathogenic taxa Prevotella and Atopobium parvulum were significantly higher during late pregnancy than preconception. Women with overall better oral hygiene practice showed lower richness     and diversity     in preconception compared to women with poorer oral hygiene practice. The abundance of pathogens such as Dialister during both preconception and pregnancy decreased among women with better oral hygiene practice.

Conclusions

The composition of the oral microbiota changed slightly from preconception to late pregnancy, with more pathogens in saliva samples during pregnancy. Improving oral hygiene practices has the potential to maintain oral micro-ecological balance.

Myrrh mixed with silver nanoparticles demonstrates superior antimicrobial activity against Porphyromonas gingivalis compared to myrrh and silver nanoparticles alone

•

Myrrh mouthwash (MM) is used against an oral health microbe that causes gingivitis.

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Adding silver nanoparticles (SN) may increase antimicrobial activity (AA).

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Our laboratory analysis compared AA between MM with and without SN.

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After 48 h, AA between MM with and without SN was similar.

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Adding SN to MM does not increase antimicrobial activity.

Introduction

Gingivitis is an oral condition characterized by inflammation and bleeding of the gingiva (gums), largely caused by Porphyromonas gingivalis. Oral hygiene options for controlling P. gingivalis include mouthwash containing Commiphora myrrha (myrrh), which has been shown to be effective against the microbe. Silver nanoparticles (SN) have been studied for their antibacterial effect in different oral health applications, including mouthwash. This was an in vitro laboratory study of the anti-microbial actions of myrrh and SN against P. gingivalis.

Methods

We compared the anti-microbial properties against P. gingivalis of four solutions: a) placebo solution, b) myrrh solution (MS), c) MS mixed with silver nanoparticles (MSN), and d) SN suspension alone. Sixteen agar plates were divided into four groups of four plates, and each group was treated with one of the solutions/suspensions. The solution/suspension was administered on the agar disc diffusion method, and inhibition zones (IZs) were measured after 24 (time 1), 48 (time 2), and 72 h (time 3). To characterize MSN and SN, Fourier-transform infrared spectroscopy (FT-IR) was used. UV–Vis spectroscopy and energy dispersive X-ray (EDX) were used to further characterize MSN.

Results

After 24 h, the median IZ for the MS plates was 16 mm, and the median IZ for MSN plates was 15 mm. At time 2, the MS median IZ was 15 mm, but the MSN median IZ increased to 18 mm, and the interquartile ranges (IQRs) did not overlap. At time 3, the median IZs was similar again, with MSN and MS having IZs of 16 mm and 15 mm, respectively. SN alone showed no anti-microbial activity.

Conclusions

Our findings show that MSN displayed superior anti-microbial activity against P. gingivalis compared to MS and SN after 48 h of incubation, but not after 24 h. Also, the increased anti-microbial activity had ceased by 72 h.

Proteomics, lipidomics, metabolomics and 16S DNA sequencing of dental plaque from patients with diabetes and periodontal disease

Oral microbiome influences human health, specifically prediabetes and type 2 diabetes (Pre-DM/DM) and periodontal diseases (PDs), through complex microbial interactions. To explore these relations, we performed 16S rDNA sequencing, metabolomics, lipidomics, and proteomics analyses on supragingival dental plaque collected from individuals with Pre-DM/DM (n = 39), Pre-DM/DM and PD (n = 37), PD alone (n = 11), or neither (n = 10). We identified on average 2790 operational taxonomic units and 2025 microbial and host proteins per sample and quantified 110 metabolites and 415 lipids. Plaque samples from Pre-DM/DM patients contained higher abundance of Fusobacterium and Tannerella than plaques from metabolically healthy patients. Phosphatidylcholines, plasmenyl phosphatidylcholines, ceramides containing non-OH fatty acids, and host proteins related to actin filament rearrangement were elevated in plaques from PD versus non-PD samples. Cross-omic correlation analysis enabled the detection of a strong association between Lautropia and monomethyl phosphatidylethanolamine (PE-NMe), which is striking because synthesis of PE-NMe is uncommon in oral bacteria. Lipidomics analysis of in vitro cultures of Lautropia mirabilis confirmed the synthesis of PE-NMe by the bacteria. This comprehensive analysis revealed a novel microbial metabolic pathway and significant associations of host-derived proteins with PD.

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Patients with periodontal disease or diabetes have unique microbial dysbiosis.

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Proteomics and 16S data provide complementary information about microbial diversity.

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Cross-omic correlation reveals host signatures associated with periodontal disease.

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Multi-omic data lead to finding about microbially synthesized lipids.

Distinct Microbiomes of Gut and Saliva in Patients With Systemic Lupus Erythematous and Clinical Associations

Alterations in the microbiome of the gut and oral cavity are involved in the etiopathogenesis of systemic lupus erythematosus (SLE). We aimed to assess whether both microbiome compositions in feces and saliva were specific in patients with SLE. A total of 35 patients with SLE, as well as sex- and age-matched asymptomatic subjects as healthy control (HC) group were recruited. Fecal swabs and saliva samples were collected from the participants. 16S ribosomal RNA gene sequencing was performed on the samples. Compared with the HC group, reduced bacterial richness and diversity were detected in the feces of patients with SLE, and increased bacterial diversity in their saliva. Both feces and saliva samples explained the cohort variation. The feces were characterized by enrichment of Lactobacillus, and depletion of an unclassified bacterium in the Ruminococcaceae family and Bifidobacterium. Lack of Bifidobacterium was observed in patients with arthritis. Akkermansia and Ruminococcus negatively correlated with the serum levels of C3. In saliva, Veillonella, Streptococcus, and Prevotella were dominant, and Bacteroides was negatively associated with disease activity. These findings can assist us to comprehensively understand the bacterial profiles of different body niches in SLE patients.

Longitudinal Multi-omics and Microbiome Meta-analysis Identify an Asymptomatic Gingival State That Links Gingivitis, Periodontitis, and Aging

A significant portion of world population still fails to brush teeth daily. As a result, the majority of the global adult population is afflicted with chronic gingivitis, and if it is left untreated, some of them will eventually suffer from periodontitis.

Most adults experience episodes of gingivitis, which can progress to the irreversible, chronic state of periodontitis, yet roles of plaque in gingivitis onset and progression to periodontitis remain elusive. Here, we longitudinally profiled the plaque metagenome, the plaque metabolome, and salivary cytokines in 40 adults who transited from naturally occurring gingivitis (NG) to healthy gingivae (baseline) and then to experimental gingivitis (EG). During EG, rapid and consistent alterations in plaque microbiota, metabolites, and salivary cytokines emerged as early as 24 to 72 h after oral-hygiene pause, defining an asymptomatic suboptimal health (SoH) stage of the gingivae. SoH features a swift, full activation of 11 salivary cytokines but a steep synergetic decrease of plaque-derived betaine and Rothia spp., suggesting an anti-gum inflammation mechanism by health-promoting symbionts. Global, cross-cohort meta-analysis revealed, at SoH, a greatly elevated microbiome-based periodontitis index driven by its convergence of both taxonomical and functional profiles toward the periodontitis microbiome. Finally, post-SoH gingivitis development accelerates oral microbiota aging by over 1 year within 28 days, with Rothia spp. depletion and Porphyromonas gingivalis elevation as hallmarks. Thus, the microbiome-defined, transient gum SoH stage is a crucial link among gingivitis, periodontitis, and aging.

Improved oral hygiene care attenuates the cardiovascular risk of oral health disease: a population-based study from Korea

AIMS

Oral health problems such as periodontal disease, dental caries, and tooth loss have been suggested to have associations with cardiovascular disease. This study aimed to evaluate whether oral hygiene behaviour can alleviate cardiovascular risk associated with oral health status using a nationwide population-based cohort.

METHODS AND RESULTS

The data of 247 696 healthy adults aged 40 years or older who underwent an oral health screening programme and had no history of major cardiovascular events were extracted from the National Health Insurance System-National Health Screening Cohort. After a median follow-up of 9.5 years, 14 893 major cardiovascular events occurred including cardiac death, myocardial infarction, stroke, and heart failure. The risk of cardiovascular events was higher when a subject had periodontal disease, a higher number of dental caries, or more tooth loss. Performing one more tooth brushing a day was associated with a 9% significantly lower risk of cardiovascular events after multivariable adjustment. Regular dental visits (once a year or more) for professional cleaning were also shown to reduce cardiovascular risk by 14%. Improved oral hygiene behaviours were shown to attenuate the cardiovascular risk originating from periodontal disease, dental caries, and tooth loss.

CONCLUSION

Oral hygiene care such as frequent tooth brushing and regular dental visits for professional cleaning reduced the risk of future cardiovascular events in healthy adults. This study also suggests that improved oral hygiene behaviour may modify the association between oral health and cardiovascular diseases.

Plaque-induced gingivitis: Case definition and diagnostic considerations

OBJECTIVE

Clinical gingival inflammation is a well-defined site-specific condition for which several measurement systems have been proposed and validated, and epidemiological studies consistently indicate its high prevalence globally. However, it is clear that defining and grading a gingival inflammatory condition at a site level (i.e. a "gingivitis site") is completely different from defining and grading a "gingivitis case" (GC) (i.e. a patient affected by gingivitis), and that a "gingivitis site" does not necessarily mean a "GC". The purpose of the present review is to summarize the evidence on clinical, biochemical, microbiologic, genetic markers as well as symptoms associated with plaque-induced gingivitis and to propose a set of criteria to define GC.

IMPORTANCE

A universally accepted case definition for gingivitis would provide the necessary information to enable oral health professionals to assess the effectiveness of their prevention strategies and treatment regimens; help set priorities for therapeutic actions/programs by health care providers; and undertake surveillance.

FINDINGS

Based on available methods to assess gingival inflammation, GC could be simply, objectively and accurately identified and graded using bleeding on probing score (BOP%) CONCLUSIONS: A patient with intact periodontium would be diagnosed as a GC according to a BOP score ≥ 10%, further classified as localized (BOP score ≥ 10% and ≤30%) or generalized (BOP score > 30%). The proposed classification may also apply to patients with a reduced periodontium, where a GC would characterize a patient with attachment loss and BOP score ≥ 10%, but without BOP in any site probing ≥4 mm in depth.

Subgingival microbiome of experimental gingivitis: shifts associated with the use of chlorhexidine and N-acetyl cysteine mouthwashes

This study aimed to demonstrate subgingival microbial changes associated with development, prevention, and treatment of experimental gingivitis using chlorhexidine (CHX) and N-acetylcysteine (NAC) mouthwashes. This randomized clinical trial comprised two parts: a 3-week prevention sub-study in which 30 study subjects were equally assigned to either mouthwash or placebo while developing experimental gingivitis; followed by a 2-week treatment sub-study in which 20 subjects with experimental gingivitis were assigned to either mouthwash. Subgingival samples were collected at the beginning and end of each sub-study for microbial profiling with 16S rRNA gene sequencing. As expected, CHX was effective in both preventing and reversing experimental gingivitis; NAC had a modest effect. Gingivitis was associated with enrichment of TM7 HOT-346/349, Tannerella HOT-286, Cardiobacterium valvarum, Campylobacter gracilis, Porphyromonas catoniae, Leptotrichia HOT-219, and Selenomonas spp. At the phylum/genus level, TM7 showed the strongest association. Gingival health was associated with increased abundance of Haemophilus parainfluenzae, Lautropia mirabilis, Rothia spp., Streptococcus spp., and Kingella oralis. CHX demonstrated largely indiscriminate antimicrobial action, resulting in significant drop in biomass and diversity. Our results substantiate the role of specific oral bacterial species in the development of gingivitis. They also indicate that NAC is not a promising mouthwash at the concentration tested.

Saccharibacteria (TM7) in the Human Oral Microbiome

Bacteria from the Saccharibacteria phylum (formerly known as TM7) are ubiquitous members of the human oral microbiome and are part of the Candidate Phyla Radiation. Recent studies have revealed remarkable 16S rRNA diversity in environmental and mammalian host-associated members across this phylum, and their association with oral mucosal infectious diseases has been reported. However, due to their recalcitrance to conventional cultivation, TM7's physiology, lifestyle, and role in health and diseases remain elusive. The recent cultivation and characterization of Nanosynbacter lyticus type strain TM7x (HMT_952)-the first Saccharibacteria strain coisolated as an ultrasmall obligate parasite with its bacterial host from the human oral cavity-provide a rare glimpse into the novel symbiotic lifestyle of these enigmatic human-associated bacteria. TM7x is unique among all bacteria: it has an ultrasmall size and lives on the surface of its host bacterium. With a highly reduced genome, it lacks the ability to synthesize any of its own amino acids, vitamins, or cell wall precursors and must parasitize other oral bacteria. TM7x displays a highly dynamic interaction with its bacterial hosts, as reflected by the reciprocal morphologic and physiologic changes in both partners. Furthermore, depending on environmental conditions, TM7x can exhibit virulent killing of its host bacterium. Thus, Saccharibacteria potentially affect oral microbial ecology by modulating the oral microbiome structure hierarchy and functionality through affecting the bacterial host's physiology, inhibiting the host's growth dynamics, or affecting the relative abundance of the host via direct killing. At this time, several other uncharacterized members of this phylum have been detected in various human body sites at high prevalence. In the oral cavity alone, at least 6 distinct groups vary widely in relative abundance across anatomic sites. Here, we review the current knowledge on the diversity and unique biology of this recently uncovered group of ultrasmall bacteria.

No differences in microbiome changes between anti-adhesive and antibacterial ingredients in toothpastes during periodontal therapy

Aim

This subgroup analysis of a 12‐week randomized, double‐blind, and two‐center trial aimed to evaluate whether two different toothpaste formulations can differentially modulate the dental microbiome.

Material and Methods

Forty one mild to moderate periodontitis patients used as an adjunct to periodontal treatment either a toothpaste with anti‐adhesive zinc‐substituted carbonated hydroxyapatite (HA) or with antimicrobial and anti‐adhesive amine fluoride/stannous fluoride (AmF/SnF₂) during a 12‐week period. Plaque samples from buccal/lingual, interproximal, and subgingival sites were taken at baseline, 4 weeks after oral hygiene phase, and 8 weeks after periodontal therapy. Samples were analyzed with paired‐end Illumina Miseq 16S rDNA sequencing. The differences and changes on community level (alpha and beta diversity) and on the level of single agglomerated ribosomal sequence variants (aRSV) were calculated with analysis of covariance (ANCOVA) and likelihood ratio test (LRT).

Results

Interproximal and subgingival sites harbored predominately Fusobacterium and Prevotella species associated with periodontitis, whereas buccal/lingual sites harbored mainly Streptococcus and Veillonella species associated with periodontal health. Alpha and beta diversity did not change noticeably differently between both toothpaste groups (P > 0.05, ANCOVA). Furthermore, none of the aRSVs showed a noticeably different change between the tested toothpastes during periodontal therapy (P_adj .> 0.05, LRT).

Conclusion

The use of a toothpaste containing anti‐adhesive HA did not induce statistically noticeably different changes on microbial composition compared to an antimicrobial and anti‐adhesive AmF/SnF₂ formulation.

Insights into the human oral microbiome

Human oral cavity harbors the second most abundant microbiota after the gastrointestinal tract. The expanded Human Oral Microbiome Database (eHOMD) that was last updated on November 22, 2017, contains the information of approximately 772 prokaryotic species, where 70% is cultivable, and 30% belong to the uncultivable class of microorganisms along with whole genome sequences of 482 taxa. Out of 70% culturable species, 57% have already been assigned to their names. The 16S rDNA profiling of the healthy oral cavity categorized the inhabitant bacteria into six broad phyla, viz. Firmicutes, Actinobacteria, Proteobacteria, Fusobacteria, Bacteroidetes and Spirochaetes constituting 96% of total oral bacteria. These hidden oral micro-inhabitants exhibit a direct influence on human health, from host's metabolism to immune responses. Altered oral microflora has been observed in several diseases such as diabetes, bacteremia, endocarditis, cancer, autoimmune disease and preterm births. Therefore, it becomes crucial to understand the oral microbial diversity and how it fluctuates under diseased/perturbed conditions. Advances in metagenomics and next-generation sequencing techniques generate rapid sequences and provide extensive information of inhabitant microorganisms of a niche. Thus, the retrieved information can be utilized for developing microbiome-based biomarkers for their use in early diagnosis of oral and associated diseases. Besides, several apex companies have shown keen interest in oral microbiome for its diagnostic and therapeutic potential indicating a vast market opportunity. This review gives an insight of various associated aspects of the human oral microbiome.

Microbiota and Metatranscriptome Changes Accompanying the Onset of Gingivitis

Over half of adults experience gingivitis, a mild yet treatable form of periodontal disease caused by the overgrowth of oral microbes. Left untreated, gingivitis can progress to a more severe and irreversible disease, most commonly chronic periodontitis. While periodontal diseases are associated with a shift in the oral microbiota composition, it remains unclear how this shift impacts microbiota function early in disease progression. Here, we analyzed the transition from health to gingivitis through both 16S v4-v5 rRNA amplicon and metatranscriptome sequencing of subgingival plaque samples from individuals undergoing an experimental gingivitis treatment. Beta-diversity analysis of 16S rRNA reveals that samples cluster based on disease severity and patient but not by oral hygiene status. Significant shifts in the abundance of several genera occurred during disease transition, suggesting a dysbiosis due to development of gingivitis. Comparing taxonomic abundance with transcriptomic activity revealed concordance of bacterial diversity composition between the two quantification assays in samples originating from both healthy and diseased teeth. Metatranscriptome sequencing analysis indicates that during the early stages of transition to gingivitis, a number of virulence-related transcripts were significantly differentially expressed in individual and across pooled patient samples. Upregulated genes include those involved in proteolytic and nucleolytic processes, while expression levels of those involved in surface structure assembly and other general virulence functions leading to colonization or adaptation within the host are more dynamic. These findings help characterize the transition from health to periodontal disease and identify genes associated with early disease.

Although more than 50% of adults have some form of periodontal disease, there remains a significant gap in our understanding of its underlying cause. We initiated this study in order to better characterize the progression from oral health to disease. We first analyzed changes in the abundances of specific microorganisms in dental plaque collected from teeth during health and gingivitis, the mildest form of periodontal disease. We found that the clinical score of disease and patient from whom the sample originated but not tooth brushing are significantly correlated with microbial community composition. While a number of virulence-related gene transcripts are differentially expressed in gingivitis samples relative to health, not all are increased, suggesting that the overall activity of the microbiota is dynamic during disease transition. Better understanding of which microbes are present and their function during early periodontal disease can potentially lead to more targeted prophylactic approaches to prevent disease progression.

Leptotrichia species in human infections II

Leptotrichia species are non-motile facultative anaerobic/anaerobic bacteria that are found mostly in the oral cavity and some other parts of the human body, in animals, and even in ocean sediments. Valid species include L. buccalis, L. goodfellowii, L. hofstadii, L. honkongensis, L. shahii, L. trevisanii, and L. wadei. Some species require serum or blood for growth. All species ferment carbohydrates and produce lactic acid that may be involved with tooth decay. Acting as opportunistic pathogens, they are involved in a variety of diseases, and have been isolated from immunocompromised but also immunocompetent individuals. Mucositis, oral lesions, wounds, and abscesses may predispose to Leptotrichia septicemia. Because identification of Leptotrichia species by phenotypic features occasionally lead to misidentification, genetic techniques such as 16S rRNA gene sequencing is recommended. Early diagnosis and treatment of leptotrichia infections is important for positive outcomes. Over the last years, Leptotrichia species have been associated with several changes in taxonomy and new associations with clinical diseases. Such changes are reported in this updated review.

A randomised clinical study to determine the effect of a toothpaste containing enzymes and proteins on plaque oral microbiome ecology

The numerous species that make up the oral microbiome are now understood to play a key role in establishment and maintenance of oral health. The ability to taxonomically identify community members at the species level is important to elucidating its diversity and association to health and disease. We report the overall ecological effects of using a toothpaste containing enzymes and proteins compared to a control toothpaste on the plaque microbiome. The results reported here demonstrate that a toothpaste containing enzymes and proteins can augment natural salivary defences to promote an overall community shift resulting in an increase in bacteria associated with gum health and a concomitant decrease in those associated with periodontal disease. Statistical analysis shows significant increases in 12 taxa associated with gum health including Neisseria spp. and a significant decrease in 10 taxa associated with periodontal disease including Treponema spp. The results demonstrate that a toothpaste containing enzymes and proteins can significantly shift the ecology of the oral microbiome (at species level) resulting in a community with a stronger association to health.