Development and establishment of oral microbiota in early life

BACKGROUND

The oral microbiota has recently attracted attention owing to its association with oral and systemic diseases. Accordingly, gaining an understanding of oral microbiota development and the factors influencing it can contribute to preventing the establishment of dysbiotic oral microbiota and, eventually, oral microbiota-related diseases.

HIGHLIGHT

In this review, we highlight the results of a longitudinal project focusing on oral microbiota development during early life. At 4 months of age, the oral microbiota of infants was found to differ considerably from the maternal oral microbiota, even though infants acquire oral bacteria from their mothers. At 18 months, although the infant microbiota is still not completely comparable with that of adults, from 4 to 18 months, there is a rapid phase of development, during which the microbial composition undergoes considerable change to a profile more similar to that in adults. During this development, the infant oral microbiota converges into two different profiles with adult-like traits, namely, Streptococcus salivarius- and Neisseria-dominant profiles. This divergence is strongly influenced by dietary habits, with a frequent intake of sweetened beverages being associated with an S. salivarius-dominant profile, which is suspected to be implicated in oral and systemic diseases.

CONCLUSION

The foundation of the adult oral microbiota may be established by 18 months of age, and the developmental period from 4 to 18 months may be an appropriate period during which to modify the microbial balance to obtain a desirable healthy state. In particular, dietary habits during this period warrant close attention.

Oral-to-rectum microbial transmission in orthopedic patients without a history of intestinal disorders

The enrichment of oral taxa in the gut has recently been reported as a notable alteration in the microbial balance in patients with intestinal disorders. However, translocation in populations without such diseases remains controversial. In this study, we examined 49 pairs of tongue and rectal samples collected from orthopedic patients without a history of intestinal disorders to verify the presence of oral taxa in the rectal microbiota. The bacterial composition of each sample was determined using 16S rRNA gene sequencing and amplicon sequence variant (ASV) analysis. Although the bacterial compositions of the tongue and rectal microbiota were distinctly different, tongue ASVs were detected in 67.3% of the participants and accounted for 0.0%-9.37% of the rectal microbiota. Particularly, Streptococcus salivarius, Fusobacterium nucleatum, and Streptococcus parasanguinis were abundant in the rectal microbiota. According to the network analysis, tongue taxa, such as S. salivarius and S. parasanguinis, formed a cohabiting group with Klebsiella pneumoniae and Alistipes finegoldii in the rectal microbiota. The total abundance of tongue ASVs in the rectal microbiota was significantly higher in participants with older age, hypertension, and proton pump inhibitor (PPI) use. Our study presents an extensive translocation of oral taxa to the rectum of a population without intestinal disorders and suggests that aging, hypertension, and PPI use are associated with an increased abundance of oral taxa and potential pathogenic bacteria in the rectal microbiota.

Establishment of tongue microbiota by 18 months of age and determinants of its microbial profile

IMPORTANCE

Understanding the development of oral microbiota early in life and the factors that influence it is important for preventing the establishment of dysbiotic oral microbiota later in life. This study demonstrates that the tongue microbiota undergoes early development from 4 to 18 months of age and converges into two types of microbiota showing indications of adult characteristics, with either S. salivarius or Neisseria-dominance. Interestingly, their divergence was strongly determined by their weaning status and the dietary frequencies of sweetened beverages, snacks, and fruits, suggesting that dietary habits during this period might influence the establishment of the oral microbiota. These findings may contribute to the development of novel preventive strategies against oral microbiota-related diseases.

High-Resolution Detection of Translocation of Oral Bacteria to the Gut

Ectopic enrichment of oral microbes in the gut is a notable alteration in gut microbial balance. These microbes are likely delivered from the oral cavity with saliva and food; however, evidence of oral-gut microbial transmission is insufficient and needs further investigation. In this observational study, we examined 144 pairs of saliva and stool samples collected from community-dwelling adults to verify the oral-gut microbial link and identify the relevant influencing factors on the increased abundance of oral microbes within the gut. The bacterial composition of each sample was determined using PacBio single-molecule long-read sequencing of the full-length 16S ribosomal RNA gene and amplicon sequence variant (ASV) analysis. Although the bacterial compositions of salivary and gut microbiota were distinctly different, at least 1 ASV was shared between salivary and gut microbiota in 72.9% of subjects. Shared ASVs accounted for 0.0% to 63.1% (median 0.14%) of the gut microbiota in each subject and frequently included abundant Streptococcus salivarius and Streptococcus parasanguinis. Their total relative abundance in the gut was significantly higher in older subjects or those with dental plaque accumulation. The gut microbiota with ≥5% of shared ASVs displayed a higher abundance of Streptococcus, Lactobacillus, and Klebsiella and a lower abundance of Faecalibacterium, Blautia, Megamonas, and Parabacteroides. Our study presents evidence for the translocation of oral bacteria to the gut in community-dwelling adults and suggests that aging and dental plaque accumulation contribute to an increased abundance of oral microbes in the gut, which might be relevant to the compositional shift in the gut commensals.

Association of second-hand smoke exposure, quantified by salivary cotinine, with dental caries in Japanese adolescents

PURPOSE

Second-hand smoke has adverse effects on oral health. This cohort study used a multilevel approach to investigate the association of second-hand smoke exposure, as determined by salivary cotinine level, with dental caries in adolescents.

METHODS

Data from 75 adolescents aged 11 or 12 years and 2,061 teeth without dental caries were analyzed in this study. Annual dental examinations to assess dental caries were conducted between 2018 and 2021. Salivary cotinine and Dentocult SM-Strip level were measured at baseline. Information on the smoking habits of parents, snack frequency, regular dental visits, and use of fluoride toothpaste was collected at baseline from parent-reported questionnaires.

RESULTS

During the 3-year follow-up, dental caries was noted in 21 adolescents and 43 teeth. Participants exposed to parental smoking had higher salivary cotinine levels than those whose parents did not smoke. The multilevel Cox regression model showed that a high salivary cotinine level was associated with the incidence of dental caries, after adjusting for potential confounding factors (hazard ratio, 3.39; 95% confidence interval 1.08-10.69).

CONCLUSION

This study suggests that the risk of dental caries is higher for adolescents who have high salivary cotinine levels attributable to second-hand smoke exposure.

Diagnostic performance of angiography-derived index of microvascular resistance: a systematic review and pooled meta-analysis

Background

The index of microvascular resistance (IMR) is an established measurement of coronary microcirculation status. However, it has not been widely incorporated into routine practice due to need for intracoronary instrumentation (pressure wire) and hyperaemic agents. Several angiography-derived quantitative flow ratio-based indexes of microvascular resistance (angio-IMR) have been proposed rekindling the interest for the assessment and management of microvascular disease.

Purpose

To review the overall diagnostic accuracy of angio-IMR against wire based IMR.

Methods

A systematic review of the literature was performed and studies comparing angio-IMR with wire based IMR were included. Individual data was extracted using semi-automatic digitalization. Correlation of angio-IMR with IMR and its diagnostic performance against IMR were analysed.

Results

Six studies directly comparing angio-IMR with IMR were included. Data extraction rate was 85.1% (582/684 vessels). There was a linear correlation between angio-IMR and IMR (β=0.483, R square=0.298) (Figure 1A). Pooled sensitivity was 77%, specificity was 66%, positive predictive value was 65%, negative predictive value was 78%, and accuracy was 71.0%. Pooled area under receiver operator curve of angio-IMR for predicting IMR diagnosed coronary microvascular disease was 0.754 (95% confidential interval 0.715 to 0.793) (Figure 1B). Similar diagnostic performance was observed in subgroups of patients with or without ST-segment elevation myocardial infarction.

Conclusions

Currently available angio-IMR showed a clearly useful discrimination and diagnostic performance against the standard of wire based IMR.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): China Scholarship Council

Geographic disparity in 10-year mortality after coronary artery revascularization in the SYNTAXES trial

Aims

To investigate geographic disparity in long-term mortality following revascularization in patients with complex coronary artery disease (CAD).

Methods and results

The SYNTAXES trial randomized 1800 patients with three-vessel and/or left main CAD to percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) and assessed their survival at 10-years. Patients were stratified according to the region of recruitment: North America (N-A, n=245), Eastern Europe (E-E: Poland, Hungary, Czech, n=189), Northern Europe (N-E: United Kingdom, Sweden, Norway, Latvia, Finland, and Denmark, n=425), Southern Europe (S-E: Spain, Portugal, and Italy, n=263), and Western Europe (W-E: Netherlands, Germany, France, Belgium, and Austria, n=678), which also served as the reference group. Compared to W-E, patients were younger in E-E (62 vs 65 years, p<0.001), and less frequently male in N-A (65.3% vs 79.6%, p<0.001). Diabetes (16.0% vs 25.4%, p<0.001) and peripheral vascular disease (6.8% vs 10.9%, p=0.025) were less frequent in N-E than W-E. Ejection fraction was highest in W-E (62% vs 56%, p<0.001). Compared to W-E, the mean anatomic SYNTAX score was higher in S-E (29 vs 31, p=0.008) and lower in N-A (26, p<0.001). Crude ten-year mortality was similar in N-A (31.6%), and W-E (30.7%), and significantly lower in E-E (22.5%, p=0.041), N-E (21.9%, p=0.003) and S-E (22.0%, p=0.014) as presented in left-middle lower of the graphical abstract. We adjusted the survival curves by following factors based on previous report; age, sex, medically treated diabetes, current smokers, peripheral vascular disease, chronic obstructive pulmonary disease, chronic kidney disease, left ventricular ejection fraction, disease type, and anatomical SYNTAX score [1]. When the differences in baseline characteristics were adjusted, mortality was still significantly lower in N-E (HR 0.85, 95% CI [0.74–0.97], p=0.019) and trended lower in S-E (HR 0.72 95% CI [0.52–0.99] p=0.043) compared to W-E (right middle-lower of the graphical abstract). However, no significant interaction (P interaction = 0.728) between region and modality of revascularization was seen.

Discussion and conclusions

The main findings of this study are:

1. Rates of crude 10-year mortality were significantly lower in E-E, N-E, and S-E compared to W-E and N-A.

2. The differences in 10-year mortality remained significantly lower with N-E and S-E even after adjustment for confounding factors.

3. However, when comparing PCI to CABG in the five geographic regions, there were no statistically significant interactions between the geographic disparity in pre- and peri-procedural characteristics and all-cause mortality.

In the era of globalization, knowledge and understanding of geographic disparity are of paramount importance for the correct interpretation of global studies.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The German Foundation of Heart Research (Frankfurt am Main, Germany)

Impact of left ventricular ejection fraction on 10-year mortality after percutaneous coronary intervention or coronary artery bypass grafting

Backgrounds

The impact on vital prognosis at very long-term of percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) in patients with reduced ejection fraction (EF) remains to be elucidated.

Objective

To investigate the impact of left ventricular ejection fraction (LVEF) on 10-year mortality after PCI and CABG in the SYNTAX trial.

Methods

In the SYNTAXES study, 1,800 randomized patients were categorized into three groups according to the current guidelines; (1) reduced EF (rEF; LVEF ≤40%), (2) mildly reduced EF (mrEF; LVEF 41–49%), (3) preserved EF (pEF; LVEF ≥50%). The primary endpoint was 10-year all-cause mortality. Event rate up to 10 years was estimated according to the Kaplan-Meier method, and the log-rank test was performed to examine the differences among LVEF subgroups. The SYNTAX score 2020 (SS-2020) was compared between the patients with reduced (LVEF <50%) and preserved EF (LVEF ≥50%) in order to better refine their respective personalized vital prognosis and assess in cross-validation the value of the risk score.

Results

The population was stratified as rEF (n=168), mrEF (n=179), and pEF (n=1453). Ten-year all-cause mortality were 44.0% vs. 31.8% vs. 22.6% (P<0.001), in patients with rEF, mrEF and pEF, respectively. The significant interaction was not identified between LVEF classification and treatment (P interaction = 0.183). In patients with rEF, there was a tendency toward higher mortality in PCI group than CABG (52.9% vs 39.6%, P=0.054), and no significant differences in patients with mrEF (36.0% vs. 28.6%, P=0.273) and pEF (23.9% vs. 22.2%, P=0.275). According to the SS-2020, PCI was a relatively safe modality of revascularization in 37.8% of the patients with reduced EF (LVEF <50%). In the population with preserved EF (LVEF ≥50%), the proportion of patients eligible to PCI with predicted equipoise in mortality with CABG was 57.5%.

Conclusion

LVEF could an important factor for determining the revascularization treatment in patients presenting with complex coronary artery disease. Calculation of individualized 10-year prognosis using the SS-2020 may be a viable option in decision-making.

Funding Acknowledgement

Type of funding sources: None.

Appropriateness of the modality of revascularization according to the SYNTAX 2020 in the FASTTRACK CABG study

Objectives

To compare the modality of revascularization selected by the local heart team to the one recommended by the core laboratory according to the SYNTAX score 2020 amongst patients with three-vessel disease (3VD) with or without left main disease (LMCAD), who were allocated to CABG planned and solely guided by coronary computerized tomographic angiography in the FASTTRACK CABG trial.

Background

Personalized long term vital prognosis plays a key role in deciding between PCI and coronary artery bypass grafting (CABG) in patients with complex coronary artery disease.

Methods

In an interim analysis requested by the Data Safety Monitoring Board the treatment recommendations according to the SYNTAX 2020 were prospectively assessed in 57 consecutive patients (half of the planned population in this First in Man) by a core laboratory and compared to the decision of the “on site” heart team.

Results

According to SS-2020, the predicted absolute risk difference (ARD) in mortality between the virtual PCI treatment population and the CABG treatment group, which can be considered a virtual surrogate for the average treatment effect, increased with the duration of follow up, from 4.8±3.5% at 5 years to 8.8±5.1% at 10 years (Table 1). The ARD of less than 0% in mortality at 5-year in favour of PCI was only documented in two patients while the 55 remaining patients had a predicted survival benefit over PCI if receiving CABG. However, based on a novel threshold of equipoise (ARD <4.5%) recently validated in a contemporary registry of 3VD and LMCAD, CABG was mandatory in 26 (45.6%) patients, whereas PCI or CABG could have been equally selected in 31 (54.4%) patients (Figure 1).

Conclusions

According to the SYNTAX Score 2020 there was a strict observance of the CABG treatment recommendation in the first 57 consecutive patients with 3VD or LMCAD, screened on site in the FAST TRACK CABG trial. The more lenient selection criteria derived from the contemporary regitry will have to be tested propectively. Application of artificial intelligence with expanded collection of baseline characteristics, scientific endorsement and regulatory enforcement as well as further prospective evaluation are the challenges of future decision-making scores, that should be ultimately shared with the patients.

Funding Acknowledgement

Type of funding sources: None.

Murray law-based quantitative flow ratio for assessment of left main bifurcation derived from a single fluoroscopic angiographic view as compared to FFRCT

Background

In patients with complex CAD, the presence of left main (LM) disease is an important prognostic factor in assessing the risk balance between PCI and CABG. Functional assessment has become standard of care to evaluate the significance of coronary stenosis and to justify the performance of PCI in the contemporary practice. FFRCT is a well-established method based on 3D reconstruction of coronary artery derived from CCTA. The Murray law-based quantitative flow reserve (μQFR) is a novel computational method of invasive angiography relying on a single angiographic view that takes into account side branches diameters to compute fractal flow division. The aim of the current analysis is to evaluate in patients with complex CAD the feasibility of μQFR in LM bifurcation and its diagnostic concordance with FFRCT. The impact of the optimal viewing angle defined by CCTA on the physiological assessment of the LM bifurcation using a single angiographic view was also evaluated.

Methods

In 299 consecutive patients with 3-vessel disease with or without LM coronary artery disease, up to 3 analyzable fluoroscopic projections per patient were analysed with μQFR retrospectively. FFRCT and μQFR were measured at 3 fiducial landmark points: i) point of LM bifurcation (POB); ii) proximal LAD 10 mm distal to POB; ii) proximal LCX 10 mm distal to POB. CCTA-based “optimal viewing angle” of LM bifurcation are computed by creating a 3-point closed spline involving the LM, LAD, and LCX at 5mm from the POB and subsequently by reconstructing the “en face” fluoroscopic viewing angle of the spline. The en face viewing angle provides an optimal assessment of the bifurcation geometry [1]. In terms of Rx gantry angulation, the closest angiographic projection to the optimal viewing angle derived from CCTA was defined as the “best fluoroscopic projection” for each patient.

Results

In 299 patients, 793 projections were analysed with μQFR and compared to FFRCT. Single view μQFR was analyzable in 100%. Correlation and agreement between μQFR and FFRCT for 793 projections in 299 patients are shown in Figure 1A, 2A. The Spearman's correlation coefficient showed moderate correlations at POB (r=0.481, p<0.001) and LCX (r=0.584, p<0.001), and strong correlation at LAD (r=0.642, p<0.001). Correlation and agreement between μQFR and FFRCT for best projections from each patient are shown in Figure 1B, 2B. Correlations were improved in the best projections with the following Spearman's correlation coefficient: at POB (r=0.522, p<0.001), LCX (r=0.622, p<0.001), and LAD (r=0.695, p<0.001).

Conclusion

Computation of μQFR from a single angiographic view has a high feasibility. Tailored optimal fluoroscopic view is essential for the physiological assessment of the LM bifurcation using a single angiographic view. Evaluation of diagnostic accuracy of μQFR warrants further analysis of the LMCAD after prospective planning of the optimal fluoroscopic view based on the selection of the best CCTA 3D view.

Funding Acknowledgement

Type of funding sources: None.

Angiographic derived physiological assessment after intervention for predicting 2-year vessel-oriented composite endpoints in Multivessel TALENT trial

Aims

The purpose of the study is to assess the treatment results in the first 200 patients in the ongoing Multivessel TALENT trial and to predict the vessel-oriented endpoint by assessing the quantitative flow ratio (QFR) post PCI in a central independent core laboratory.

Methods

In this prospective, randomized, 1:1 balanced, multi-centre, open-label trial, de novo multivessel coronary artery disease patients without left main disease are assigned to the sirolimus-eluting stent or everolimus-eluting stent arm. The percutaneous coronary intervention (PCI) is planned based on functional lesion evaluation by QFR provided by the Core laboratory and the PCI has to be optimized by intravascular imaging, optimal pharmacological treatment and prasugrel monotherapy.

Results

Mean age of the population was 66.6±14.7 years, and 78.1% of them were male. This population consists of 17.4% unstable angina and of 31.8% diabetic patients. Anatomical SYNTAX score was 18.8±9.1. Total 458 lesions were treated from September 2020 to December 2021. Left anterior descending artery accounts for 40.3%, bifurcation lesion was present in 40.8%, total occlusion in 4.2%. The average stent diameter and total stent length were 3.0±0.4mm and 38.7±22.4mm, respectively. Intravascular imaging was used in 92.8% of treated vessels (intravascular ultrasound 56.5%, optical coherent tomography 36.3%). Pre-PCI QFR was analysable in 435 vessels (0.59±0.21), and 5.5% of them were treated even though the pre-PCI QFR values were more than 0.8. Post-PCI QFR has been so far analysed in 303 vessels (0.93±0.11) and 79.5% of them achieved a post-PCI QFR equal or superior to 0.91. Based on the previous study [1], Two-year vessel-oriented composite endpoint (VOCE) was estimated to become 5.4% in the present study population (3.7% in the patient group that achieved post PCI QFR equal or superior to 0.91, while 12% in the patients who could not reach the threshold), which was almost equal to what is expected in the power calculation.

Conclusions

In the Multivessel TALENT trial, the large majority of the vessels treated (94.5%) complied with the hemodynamic criteria of recommended PCI as provided by the QFRs of the Core laboratory. Favourable post-PCI QFR (≥0.91) obtained in 80% of the patients let expected a favourable VOCE outcome of 5.4%.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): The National University of Ireland Galway

Comparison of the SYNTAX score 2020 based on Coronary Artery Computed Tomography (CCTA) with Invasive Coronary Angiography (ICA)

Introduction

The SYNTAX III REVOLUTION trial demonstrated that clinical decision-making between coronary artery bypass graft (CABG) and percutaneous coronary intervention (PCI) based on coronary artery computed tomography (CCTA) and predicting four years mortality according to the SYNTAX score II had a high agreement with the treatment decision derived from invasive coronary angiography (ICA). The agreement of the novel SYNTAX score 2020 (SS-2020) based on CCTA and ICA has not yet been evaluated in a prospective fashion.

Methods

This study included 54 consecutive patients in the ongoing FASTTRACK CABG trial that investigates decision making, planning and procedural CABG guidance based solely on CCTA and FFRct. All the patients underwent CCTA and ICA, and SS-2020 was calculated based on the results of anatomical SYNTAX score derived from either CCTA or ICA, and the respective scores were compared by using paired t-test.

Results

The mean age was 67.3±9.7, and 48 were men (88.9%). Anatomical SYNTAX score derived from CCTA was assessed in the 54 cases (analysability 100%). Anatomical SYNTAX scores based on CCTA and ICA were 34.3±9.3, and 35.5±11.3, respectively (P=0.480). As shown in the table predicted 5 years major adverse cardiac and cerebrovascular events (MACCE) following either PCI or CABG, as well as predicted 10 years mortality following CABG differed significantly. However the absolute risk differences (ARD) in 5 years MACCE and 10 years mortality following either PCI or CABG, were comparable.

Conclusions

High agreements were confirmed in the calculations of anatomical SYNTAX scores with CCTA and ICA. Despite significant differences in predicted MACCE rates at 5 years and mortalities at 10 years, the ARD in MACCE rates and mortality were comparable. In terms of treatment decision-making, SS-2020 calculations based on CCTA is a non-invasive predictive tool comparable to the one based on ICA.

Funding Acknowledgement

Type of funding sources: None.

Yogurt product intake and reduction of tooth loss risk in a Japanese community

Aim

To evaluate the longitudinal association between yogurt product intake and oral health in a population‐based study.

Materials and Methods

This study included 1967 Japanese residents aged 40–79 years who underwent dental examinations in 2012. Among them, 1469 participants were followed up in 2017 for the incidence of tooth loss, which was defined as two or more teeth lost over 5 years. The intake of yogurt products, defined as yogurt and lactic acid beverages, was estimated using a semi‐quantitative food frequency questionnaire. The composition of the salivary microbiota was evaluated.

Results

The Poisson regression model showed that a higher intake of yogurt products was negatively associated with the incidence of tooth loss (p for trend = .020), adjusted for potential confounding factors. Mediation analysis confirmed that periodontal condition partly mediated the effect of yogurt product intake on tooth loss, while dental caries experience did not. Additionally, we confirmed the association of a high intake of yogurt products with a low percentage of the salivary microbiota pattern, which was associated with poor oral health.

Conclusion

These findings suggest that the intake of yogurt products is associated with a lower risk of tooth loss resulting from periodontal disease, probably via modulation of the oral microbiome composition.

Baseline periodontal status and modifiable risk factors are associated with tooth loss over a 10-year period: estimates of population attributable risk in a Japanese community

Background

This study aimed to examine whether modifiable risk factors can predict tooth loss over 10 years and estimate population attributable risk (PAR) for a combination of modifiable factors.

Methods

This longitudinal study included 1466 participants who underwent dental examinations in 2007 and 2017 and were aged 40 to 79 years at baseline. Periodontal conditions were assessed using the 2018 periodontal classification. Incident tooth loss was defined as ≥4 teeth lost over a 10‐year period. We calculated the partial PAR (pPAR%) for tooth loss to estimate the combined effect of modifiable risk factors.

Results

Incidence of tooth loss was 17.5%. Directed acyclic graphs were used to identify risk factors for tooth loss. A logistic regression model showed that baseline periodontitis, dental caries experience, no regular dental visit, periodontal treatment, smoking, and obesity were associated with tooth loss after adjusting for covariates; pPAR% was 55.5% (95% confidence interval: 31.1% to 73.0%) in periodontitis Stage III to IV and 87.6% (50.4% to 97.4%) in the combination of all factors, respectively. The sex‐stratified analysis showed that smoking and no regular dental visit in men and obesity in women were identified as potential risk factors for tooth loss.

Conclusions

Modifiable factors accounted for most cases of incident tooth loss. Risk factors for tooth loss might differ by sex, suggesting that the appropriate approach for preventing tooth loss base on sex.

10-year trend of tooth loss and associated factors in a Japanese population-based longitudinal study

OBJECTIVES

We examined the trend in the number of missing teeth in a Japanese community over a 10-year period and the potential associated explanatory factors.

DESIGN

Prospective cohort study.

SETTING

A population-based study conducted in 2007, 2012 and 2017 in Japan (Hisayama Study).

PARTICIPANTS

Residents of a Japanese community aged 40-79 years undergoing dental examination in 2007 (n=2665), 2012 (n=2325) and 2017 (n=2285).

OUTCOME MEASURES

The number of missing teeth, periodontal condition, dental caries experience, dental plaque index and oral health behaviours were evaluated each year. The longitudinal analysis of variation in these factors were assessed using mixed models.

RESULTS

The age-adjusted and sex-adjusted mean number of missing teeth decreased with time (6.80 in 2007, 6.01 in 2012 and 4.99 in 2017). The mean clinical attachment level (CAL), prevalence of periodontitis and dental plaque index decreased over the study period, while dental caries experience slightly increased. The level of oral health behaviour increased over time. Poisson mixed models showed that changes in mean CAL and dental caries experience were positively associated with the change in the number of missing teeth over time. Linear mixed models showed that changes in dental plaque index and no regular dental visit were positively associated with changes in mean CAL.

CONCLUSIONS

These findings suggest that a decreasing trend regarding the number of missing teeth in Japan might be associated with improvements in the periodontal condition due to changes in oral hygiene level and oral health behaviour.

Clinical utility of subgingival plaque-specific bacteria in salivary microbiota for detecting periodontitis

Saliva contains diverse bacteria shed from various oral sites, including subgingival plaque. It is reasonable to focus on the total occupancy of subgingival plaque-specific bacteria (SUBP bacteria), which live in subgingival environments, in the saliva for detecting periodontitis using salivary testing. This study aimed to validate the clinical utility of SUBP bacteria in the salivary microbiota for the detection of periodontitis. We examined stimulated saliva samples collected from 125 subjects who visited three dental clinics. The relative abundances of previously identified 11 SUBP bacteria were determined using 16S ribosomal RNA gene sequencing and a reference-based approach. The prediction performance was evaluated using a receiver operating characteristic (ROC) curve. The SUBP bacteria accounted for 0-15.4% of the salivary microbiota, and the percentage distinguished periodontitis patients with at least 15 sites with probing depth ≥4 mm with a sensitivity of 0.90 (95% confidence interval [CI], 0.81-0.98) and specificity of 0.70 (95% CI, 0.60-0.80) (area under the ROC curve [AUC], 0.87). Among 2,047 combinations of 11 SUBP bacteria, combinations including Streptococcus constellatus, Porphyromonas gingivalis, and Fusobacterium nucleatum subsp. vincentii demonstrated significantly higher AUC values in their detection. These results suggest that examining SUBP bacteria in saliva may be useful for detecting periodontitis patients in mass screening.

Airflow limitation and tongue microbiota in community-dwelling elderly individuals

Numerous oral indigenous microorganisms are constantly introduced into the stomach via the laryngopharynx, and a portion of these microorganisms irregularly reaches the lower airways and lungs. This study investigated the association between airflow limitation and the status of tongue microbiota, which is a primary source of ingested oral bacterial populations.

The study population consisted of 484 community-dwelling adults aged 70–80 years inhabiting Hisayama town, Japan, who underwent a regular health examination including dental examination and spirometry test in 2016. The bacterial density and composition of their tongue microbiota were determined using a previously used 16S rRNA gene to understand their relationship with oral health conditions. The present cross-sectional study compared the tongue microbiota status between elderly individuals with airflow limitation and those with normal airflow.

The total bacterial density of the tongue microbiota of individuals with airflow limitation was significantly higher than that of individuals with normal airflow. Logistic regression analysis demonstrated that a high-biomass tongue microbiota was significantly associated with airflow limitation after adjustment for smoking intensity and other covariates (adjusted OR 1.61, 95% CI 1.01–2.60). Of the predominant commensals, higher amounts of Prevotella melaninogenica and Actinomyces odontolyticus were associated with a higher prevalence of airflow limitation.

These results indicate that increased bacterial burden in the tongue microbiota is associated with a higher prevalence of airflow limitation.

Bacterial enrichment in the tongue microbiota is associated with airflow limitation characterising COPD in community-dwelling elderly adultshttps://bit.ly/36qMf6G

Compositional Shift of Oral Microbiota Following Surgical Resection of Tongue Cancer

Salivary microbiota is considered a source of microorganisms for the respiratory and digestive tracts, and a trigger for diseases in these distant organs. Meanwhile, the microbiota on the tongue surface is thought to be a major source of salivary microbiota. Therefore, surgical resection of the tongue for definitive treatment of oral cancer could drastically change the salivary bacterial balance and virulence. Here, we investigated the shift of the salivary microbiota following surgical resection in patients with tongue cancer. The stimulated saliva samples were collected from 25 tongue cancer patients pre- and post-resection of the tongue, and bacterial density and composition was determined using quantitative PCR analysis and 16S ribosomal RNA (rRNA) gene sequencing, respectively. Although no significant difference in the total bacterial density in saliva pre- and post-surgery was observed, the bacterial composition significantly differed according to the analysis of similarity. Among predominant operational taxonomic units (OTUs) with ≥1% of relative abundance, the proportions of OTUs corresponding to Streptococcus salivarius, Prevotellamelaninogenica, and Prevotellahisticola were significantly decreased following the tongue resection. On the other hand, the proportions of OTUs corresponding to Lautropiamirabilis, Neisseriaflava, Streptococcussanguinis, and Fusobacterium nucleatum, known to be inhabitants of dental plaque, were significantly increased. These results suggest that surgical resection of the tongue causes a compositional shift of the salivary microbiota, characterized by an increase in bacterial species derived from dental plaque, including periodontal pathogens. These results suggest the necessity of more careful and frequent postoperative oral care after surgical resection of tongue cancer.

Risk stratification on admission for predicting death or need for surgery in patients with acute type A intramural hematoma receiving medical therapy – validation cohort

Background

There has been continuing discussion regarding the treatment strategy for acute type A intramural hematoma (IMH). We previously examined the risk factors of death or need for surgery for acute type A IMH in patients receiving medical treatment using clinical findings on hospital arrival and developed a simple risk score using the factors.

Purpose

We examined the accuracy of the risk score in the validation cohort.

Methods

From 2009 to 2014, 57 consecutive patients diagnosed with acute type A IMH who were receiving initial medical treatment were retrospectively included for derivation cohort. Primary endpoint was a composite of cardiovascular death and operation within 1 year after onset. On admission, the primary endpoint could be predicted with 89.7% sensitivity and 75% specificity if the patient had ulcer-like projection (ULP) and/or ≥2 of the following factors: systolic blood pressure (SBP) <120 mmHg, ascending aorta diameter>45 mm, and pericardial effusion (PE). In the current study, validation cohort study was performed from 2015 to 2020 in 73 consecutive patients who met the same inclusion criteria for derivation cohort to evaluate the risk factors and the accuracy of the risk score.

Result

Mean age of onset was 74 years old. Mean SBP on arrival was 134 mmHg. Computed tomography (CT) on arrival showed a mean ascending aorta diameter of 46 mm. ULP and PE were seen in 27% and 41% of cases, respectively. Thirty-three patients (45.2%) reached the primary endpoint (cardiovascular death, 8 cases [11%]; operation, 25 cases [34.2%]). In univariate analysis of admission values, the primary endpoint group had significantly lower SBP (116±29 vs 147±35 mmHg), higher ascending aorta diameter (49±8 vs 45±9 mm), and higher frequency of ULP (50% vs 10%) and PE (56% vs 29%) than did the event-free group. Multivariate analysis showed that ULP and SBP were significant predictors of the primary endpoint. The total risk score ≥2 could predict the primary endpoint with 87.5% sensitivity and 71.7% specificity (area under the receiver operating characteristic curve, 0.791).

Conclusion

The risk score was useful to predict cardiovascular death and the need for surgery in patients with acute type A IMH receiving medical therapy in the validation cohort study.

ROC curve for the risk score

Funding Acknowledgement

Type of funding source: None

Disrupted tongue microbiota and detection of nonindigenous bacteria on the day of allogeneic hematopoietic stem cell transplantation

Disruption of the intestinal microbiota caused by intensive chemotherapy, irradiation and antibiotics can result in development of severe gut graft-versus-host disease and infectious complications, leading to poorer outcomes among allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Although the oral cavity is also densely colonized by indigenous microorganisms, the bacterial composition in allo-HSCT recipients remains unclear. We determined the tongue microbiota composition of 45 patients with hematological disorders on the day of transplantation and compared them to 164 community-dwelling adults. The V1–V2 regions of the 16S rRNA gene sequences demonstrated that the allo-HSCT recipients had less diverse and distinct microbiota from that of community-dwelling adults. The full-length 16S rRNA gene sequences identified 146 bacterial taxa in the microbiota of allo-HSCT recipients, of which 34 bacterial taxa did not correspond to bacteria primarily inhabiting the oral cavity deposited in the expanded Human Oral Microbiome Database. Notably, the detection of Staphylococcus haemolyticus and/or Ralstonia pickettii was significantly associated with a higher risk of mortality during the follow-up period. These results demonstrate that the oral cavity of allo-HSCT recipients is colonized by a disrupted microbiota on the day of transplantation and suggest that detection of specific nonindigenous taxa could be a predictor of transplant outcome.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients are subjected to intensive chemotherapy, irradiation and antibiotics which could affect the intestinal as well as oral microbiota. We employed full-length 16S rRNA gene sequencing analysis with high taxonomic resolution using a third-generation sequencer, PacBio Sequel, and determined the bacterial composition of the tongue microbiota of allo-HSCT recipients after conditioning regimens. This comprehensive molecular approach identified 34 taxa uncommon in the oral cavity, which constituted 0–99.4% (median, 0.27%) of each tongue microbiota. Of them, Staphylococcus haemolyticus and Ralstonia pickettii were frequently found in allo-HSCT recipients, and their detection was significantly associated with a higher risk of mortality during the follow-up period. These results suggest that careful attention should be given to the bacterial composition of the disrupted oral microbiota in allo-HSCT recipients.

Relationships of Variations in the Tongue Microbiota and Pneumonia Mortality in Nursing Home Residents

Background

Aspiration of oral debris, containing dense oral bacteria, is a major cause of pneumonia in elderly adults. This study investigated the relationship between tongue microbiota composition and incidence of pneumonia-related deaths, in nursing home residents.

Methods

The subjects were assessed for health conditions, including their tongue microbiota, at baseline. We determined tongue microbiota profiles by 16S ribosomal RNA gene sequencing and clustering approach. All subjects (n = 173) were followed prospectively for a median of 19 months to assess the incidence of all-cause death, including pneumonia-related death. We evaluated risk estimates of microbiota effects on death using multivariate Cox proportional hazards regression analysis.

Results

Tongue microbiota were classified into two community types: type I was dominated by Prevotella and Veillonella species, while type II was dominated by Neisseria and Fusobacterium species. The subjects with type I microbiota exhibited a significantly greater risk of all-cause death (adjusted hazard ratio [aHR] = 3.79, 95% confidence interval [CI] = 1.38-10.39) and pneumonia-related death (aHR = 13.88, 95% CI = 1.64-117.21), than those with type II microbiota. There was no significant association between microbiota type and other-cause death.

Conclusions

The tongue microbiota type was significantly associated with an increased mortality risk from pneumonia in nursing home residents.

Effect of coffee on the compositional shift of oral indigenous microbiota cultured in vitro

Coffee is a widely consumed beverage containing organic compounds with antibacterial activity. To investigate its possible effect on the growth of oral indigenous microbiota, saliva samples collected from nine young adults were inoculated into brain heart infusion (BHI) medium with or without addition of coffee compounds and cultured at 37°C in 5% CO₂ for 12 h. The total bacterial density and composition after cultivation for 0, 6, and 12 h were determined by quantitative PCR analysis and 16S rRNA gene sequencing, respectively. The increase in total bacterial load was significantly inhibited by addition of the coffee compounds. The microbiota was mostly composed of Streptococcus species after culture in BHI medium regardless of the addition of coffee compounds. The proportion of Streptococcus salivarius was significantly reduced after addition of coffee relative to that in untreated medium alone, whereas the proportions of Streptococcus mitis and Streptococcus infantis were increased. These results suggest that exposure to coffee affects the composition of the oral Streptococcus population, in addition to inhibiting the overall growth of salivary bacteria. Considered in the light of data from earlier epidemiological studies, it is possible to conclude that coffee consumption contributes to better health.

Characteristics of the Salivary Microbiota in Patients With Various Digestive Tract Cancers

The salivary microbiota is constantly swallowed and delivered to the digestive tract. These bacteria may be associated with gastrointestinal diseases. This case-control study examined the salivary microbiota in patients with digestive tract cancer (DTC) and evaluated their differential distribution based on the cancer sites. We collected saliva samples from 59 patients with cancer in any part of the digestive tract (tongue/pharynx, esophagus, stomach, and large intestine) and from 118 age- and sex-matched control subjects. There was no significant difference in periodontal status between DTC patients and control subjects (P = 0.72). We examined the bacterial diversity and composition in saliva by 16S ribosomal RNA gene sequencing. Salivary bacterial diversity in DTC patients was significantly higher than that in control subjects [number of operational taxonomic units (OTUs), P = 0.02; Shannon index, P < 0.01; Chao1, P = 0.04]. Eleven differentially abundant OTUs in DTC patients were identified using the linear discriminant analysis effect size (LEfSe) method. Based on the cancer sites, the diversity of salivary bacteria was especially higher in tongue/pharyngeal or esophageal cancer patients than in control subjects. Among the 11 differentially abundant OTUs in DTC patients, an OTU corresponding to Porphyromonas gingivalis was more abundant in the saliva of all groups of DTC patients compared to that in control subjects, and an OTU corresponding to Corynebacterium species was more abundant in all groups other than gastric cancer patients (P < 0.01). In addition, the relative abundances of OTUs corresponding to Fusobacterium nucleatum, Streptococcus parasanguinis II, and Neisseria species were significantly higher in tongue/pharyngeal cancer patients compared to their abundances in control subjects (P < 0.01). The relative abundance of an OTU corresponding to the Neisseria species was also significantly higher in gastric cancer patients and that of an OTU corresponding to Actinomyces odontolyticus was significantly higher in colorectal cancer patients (P < 0.01). These results suggest that the salivary microbiota might be associated with various digestive tract cancers.

78 Evaluation of the genomic estimated breeding value of carcass traits in blastocyst-stage embryos derived from Japanese Black cattle

Genomic selection based on a high-throughput microarray for genotyping single nucleotide polymorphism (SNP) is expected to accelerate genetic improvement in cattle. Recently, a genomic evaluation system for carcass traits, such as carcass weight and marbling score, is being established in Japanese Black cattle. To further increase genetic improvement efficiency in this breed, establishing a genomic evaluation system for pre-implantation embryos before embryo transfer (ET) is required. Here, we examined the correlation between genomic estimated breeding value (GEBV) of carcass traits calculated from embryonic (blastocyst) biopsy cells and from a corresponding calf produced by ET (Experiment 1); we also evaluated the pregnancy rate following ET of GEBV-evaluated blastocysts (GEBV blastocysts) preserved by vitrification (Experiment 2). In total, 16 Japanese Black dams and cryopreserved semen from 6 Japanese Black sires were used for producing in vivo blastocysts (Day 7-8). In Experiment 1, four blastocysts (IETS code 1) were divided into biopsy cells (15-20 cells) and biopsied embryos using a micromanipulator equipped with a micro blade. Biopsy cells were processed for DNA extraction and whole-genome amplification. Freshly biopsied embryos were transferred to recipient cows, and DNA was extracted from the blood or ear cells of the resulting 4 calves. Then SNP genotyping was performed using Illumina bovine LD BeadChip (Illumina, San Diego, CA, USA). The GEBV of 6 carcass traits (carcass weight, ribeye area, rib thickness, subcutaneous fat thickness, estimated yield percent, and marbling score) were calculated using phenotypic and genotypic data from 4,311 Japanese Black steers, and these were compared between biopsy cells and the corresponding calf. In Experiment 2, 134 blastocysts (IETS code 1 and 2) in total were biopsied (10-20 cells), and the biopsied embryos were vitrified by the cryotop method. Biopsy cells were processed for SNP genotyping as in Experiment 1, and the samples in which the call rate was more than 85% were used for GEBV calculation. Based on GEBV records, 24 vitrified GEBV blastocysts were warmed, cultured for 3 to 5h, and 22 GEBV blastocysts that survived (re-expanded) post-culture were transferred to recipient cows. Pregnancy in these cows was diagnosed using ultrasonography during Day 55 to 60 of gestation. In Experiment 1, the SNP call rates of the biopsy cells and corresponding calf were 98.5 to 99.3% and 99.7 to 99.8%, respectively. The GEBV of 6 carcass traits from biopsy cells and from the corresponding calf had almost the same values. In Experiment 2, the SNP call rates of the biopsy cells were ranged from 26.1 to 99.3%. The GEBV of 6 carcass traits varied among full-sib embryos. The pregnancy rate following ET of vitrified GEBV blastocysts was 40.9% (9/22). These results suggest the possible application of a genomic evaluation system for carcass traits at the blastocyst stage in Japanese Black cattle. Further large-scale assessment of pregnancy rates following ET of cryopreserved GEBV blastocysts is required for practical application of the evaluation system.

Decreased cognitive function is associated with dysphagia risk in nursing home older residents

OBJECTIVE

To examine the association between cognitive function and dysphagia risk among Japanese nursing home residents.

BACKGROUND

Reduction in cognitive function can influence the intake of food during swallowing, and may be an aggravating factor in dysphagia.

METHODS

This cross-sectional study included 236 residents aged ≥60 years from eight nursing homes. Screening of dysphagia, especially aspiration risk, was conducted using the Modified Water Swallow Test, whose scores from one to three were classified as at risk of dysphagia. Cognitive function was evaluated using Mini-Mental State Examination (MMSE). Number of teeth and occlusal support were evaluated by clinical examination. The participants were stratified into dentulous and edentulous groups, because the number of teeth could influence swallowing function. The odds ratio (OR) and 95% confidence interval (CI) for dysphagia risk based on the scores of MMSE were calculated using logistic regression. Demographic characteristics, activity of daily living, comorbidities, health behaviour and occlusal support were used as covariates.

RESULTS

Among the 236 participants (111 dentulous participants and 125 edentulous participants) included in our analysis, 16.9% belonged to risk of dysphagia. Dentulous participants with higher scores of MMSE tended to have significantly lower odds of dysphagia risk after adjusting for covariates (OR = 0.87, 95% CI = 0.80-0.96). Despite the lack of significant differences, edentulous participants with higher score of MMSE tended to have lower odds of dysphagia risk (OR = 0.92, 95% CI = 0.83-1.00).

CONCLUSION

Decreased cognitive function may be an independent predictor of dysphagia among dentulous and edentulous adults.

Characterization of oral microbiota and acetaldehyde production

Background: Neisseria has been reported to be a high producer of acetaldehyde (ACH), a carcinogen, from ethanol in vitro, but no information exists regarding whether the ACH production depends on oral microbiota profiles. Objective and Design: To explore the salivary microbiota profiles with respect to ACH production ability in the oral cavity using a cross-sectional design. Results: Using 16S rRNA gene amplicon sequencing, we classified 100 saliva samples into two types of communities (I and II). Salivary ACH production ability from ethanol was measured using gas chromatography and was found to vary over a 30-fold range. ACH production ability was significantly higher in the type I community, wherein the relative abundance of Neisseria species was significantly lower. Multivariate logistic regression analysis showed that the subjects with the type I community exhibited significantly higher probability of high ACH production ability than those with the type II community (P = 0.014). Moreover, the relative abundance of Neisseria species was inversely correlated with the ACH production ability (P = 0.002). Conclusion: The salivary microbiota profile with a lower relative abundance of Neisseria species was independently associated with high ACH production ability, despite Neisseria species are dominant producers of ACH in vitro.

Metabotropic glutamate receptor subtype 7 has critical roles in regulation of the endocrine system and social behaviours

Metabotropic glutamate receptor subtype 7 (mGluR7) is one of the group III mGluRs, which are negatively coupled to adenylate cyclase via Gi/Go proteins and localised to presynaptic active zones of the mammalian central nervous system. We previously reported that mGluR7 is essential for intermale aggression and amygdala-dependent fear learning. To elucidate the role of mGluR7 in the neuroendocrine system, we performed biochemical analyses and found a significant reduction of testosterone levels in mGluR7 knockout (KO) mice. Testosterone replacement restored intermale aggressive behaviour in castrated wild-type mice to the level of gonadally intact wild-type mice. However, given the same dosage of testosterone replacement, mGluR7 KO mice showed almost no aggressive behaviour. These results indicate that reduction of plasma testosterone is unrelated to the deficit in intermale aggression in mGluR7 KO mice. Social investigating behaviour of intact mGluR7 KO mice also differed from that of wild-type mice; e.g. the KO mice showing less frequent anogenital sniffing and more frequent grooming behaviour. Testosterone replacement increased anogenital sniffing and grooming behaviour in castrated mGluR7 KO mice, while the differences were still present between castrated wild-type mice and KO mice after both underwent testosterone replacement. These results imply that reduction of plasma testosterone may partially inhibit social investigating behaviours in intact mGluR7 KO mice. Furthermore, castrated mGluR7 KO mice have smaller seminal vesicles than those of castrated wild-type mice, although seminal vesicle weights were normal in intact mice. These observations suggest that, besides testicular testosterone, some other hormone levels may be dysregulated in mGluR7 KO mice, and indicate a critical role of mGluR7 in the endocrine system. Taken together, our findings demonstrate that mGluR7 is essential for the regulation of the endocrine system, in addition to innate behaviours such as intermale aggression and fear response.

Impact of Subnormothermic Machine Perfusion Preservation in Severely Steatotic Rat Livers: A Detailed Assessment in an Isolated Setting

The current drastic shortage of donor organs has led to acceptance of extended-criteria donors for transplantation, despite higher risk of primary nonfunction. Here, we report the impact of subnormothermic machine perfusion (SMP) preservation on the protection of >50% macrosteatotic livers. Dietary hepatic steatosis was induced in Wistar rats via 2-day fasting and subsequent 3-day re-feeding with a fat-free, carbohydrate-rich diet. This protocol induces 50-60% macrovesicular steatosis, which should be discarded when preserved via cold storage (CS). The fatty livers were retrieved and preserved for 4 h using either CS in histidine-tryptophan-ketoglutarate or SMP in polysol solution. Graft functional integrity was evaluated via oxygenated ex vivo reperfusion for 2 h at 37°C. SMP resulted in significant reductions in not only parenchymal alanine aminotransferase (p < 0.001), but also mitochondrial glutamate dehydrogenase (p < 0.001) enzyme release. Moreover, portal venous pressure (p = 0.047), tissue adenosine triphosphate (p = 0.001), bile production (p < 0.001), high-mobility group box protein-1 (p < 0.001), lipid peroxidation, and tissue glutathione were all significantly improved by SMP. Electron microscopy revealed that SMP alleviated deleterious alterations of sinusoidal microvasculature and hepatocellular mitochondria, both of which are characteristic disadvantages associated with steatosis. SMP could protect 50-60% macrosteatotic livers from preservation/reperfusion injury, and may thus represent a new means for expanding available donor pools.

Relative abundance of total subgingival plaque-specific bacteria in salivary microbiota reflects the overall periodontal condition in patients with periodontitis

Increasing attention is being focused on evaluating the salivary microbiota as a promising method for monitoring oral health; however, its bacterial composition greatly differs from that of dental plaque microbiota, which is a dominant etiologic factor of oral diseases. This study evaluated the relative abundance of subgingival plaque-specific bacteria in the salivary microbiota and examined a relationship between the abundance and severity of periodontal condition in patients with periodontitis. Four samples (subgingival and supragingival plaques, saliva, and tongue coating) per each subject were collected from 14 patients with a broad range of severity of periodontitis before periodontal therapy. The bacterial composition was analyzed by 16S rRNA gene amplicon sequencing using Ion PGM. Of the 66 species-level operational taxonomic units (OTUs) representing the mean relative abundance of ≥ 1% in any of the four niches, 12 OTUs corresponding to known periodontal pathogens, including Porphyromonas gingivalis, were characteristically predominant in the subgingival plaque and constituted 37.3 ± 22.9% of the microbiota. The total relative abundance of these OTUs occupied only 1.6 ± 1.2% of the salivary microbiota, but significantly correlated with the percentage of diseased sites (periodontal pocket depth ≥ 4 mm; r = 0.78, P < 0.001), in addition to the abundance of subgingival plaque microbiota (r = 0.61, P = 0.02). After periodontal therapy, the total relative abundance of these 12 OTUs was evaluated as well as before periodontal therapy and reductions of the abundance through periodontal therapy were strongly correlated in saliva and subgingival plaque (r = 0.81, P < 0.001). Based on these results, salivary microbiota might be a promising target for the evaluation of subgingival plaque-derived bacteria representing the present condition of periodontal health.

141 EXPRESSION STATUS OF AQUAPORINS 3, 7, AND 9 IN BOVINE PRE-IMPLANTATION EMBRYOS

The aquaporins (AQP) are a family of small integral membrane proteins that work as channels for rapid water transport. In mouse embryos, AQP3, AQP7, and AQP9 were found to play important roles in the pre-implantation development or adaptive cellular response to osmotic stress. In addition, because AQP3, AQP7, and AQP9 permeate not only water but also cryoprotectant, such as glycerol, these AQP thought to be involved in the process of cryopreservation. However, little information is available for AQP in bovine embryos. The understanding of the mechanisms mediated by AQP that embryos utilise to survive during culture and the process of cryopreservation will contribute to development of in vitro culture systems and cryopreservation procedures for bovine embryos. The aims of present study were to clarify the expression status of AQP3, AQP7, and AQP9 in bovine pre-implantation embryos, and to evaluate the expression level of AQP3 in in vivo-derived (IVD) and IVF bovine embryos. For production of IVF embryos, cumulus-oocyte complexes (COC) were aspirated from ovaries collected at a local slaughterhouse. The COC were in vitro matured, fertilized, and then cultured for 7 days. The IVD embryos at early blastocyst (EB) and blastocyst (BC) stage were obtained from donor cows treated with superovulation and AI. In experiment 1, in order to clarify the expression of AQP3, AQP7, and AQP9 mRNA in bovine pre-implantation embryos, total RNA was extracted from pools of 30 IVM oocytes, pools of 15 IVF embryos at 2- to 4-cell, 8- to 16-cell, compaction morula (CM), EB, BC, and expanded blastocyst (ExBC) stage, and RT-PCR was performed followed by agarose gel electrophoresis. In experiment 2, in order to clarify the expression status of AQP3, AQP7, and AQP9 during bovine pre-implantation development after zygotic gene activation, total RNA was extracted from pools of 15 IVF embryos at 8- to 16-cell, CM, EB, BC and ExBC stage (n = 5), and relative quantifications of AQP mRNA were performed using real-time RT-PCR. Data were analysed by Scheffé’s method. In experiment 3, AQP3 transcript levels in single IVD and IVF embryos at EB and BC stages (n = 10) was evaluated by real-time RT-PCR. Data were analysed by Mann-Whitney’s U test. In experiment 1, AQP3 and AQP7 transcripts were detected in IVM oocytes and all stages of embryos. AQP9 mRNA was detected in IVM oocytes and in 2- to 4-cell, 8- to 16 cell, CM, and EB stage embryos, but was not detected in BC and ExBC stage embryos. In experiment 2, AQP3 and AQP7 transcript levels were significantly increased from 8- to 16-cell to CM and EB stage, and significantly decreased from EB to BC and ExBC stages (P < 0.05). AQP9 transcript level was significantly decreased from 8- to 16-cell to CM and EB stage (P < 0.05). In experiment 3, AQP3 transcript level in IVF embryos was significantly lower than that in in vivo embryos at the BC stage (P < 0.05). Our results indicate that AQP3 and AQP7 may have specific roles at morula and EB stage in bovine embryos. In addition, AQP3 expression is influenced by developmental condition of bovine embryos.

Posterior Teeth Occlusion Associated with Cognitive Function in Nursing Home Older Residents: A Cross-Sectional Observational Study

Early detection and subsequent reduction of modifiable risk factors for cognitive decline is important for extending healthy life expectancy in the currently aging society. Although a recent increase in studies on the state or number of the teeth and cognitive function, few studies have focused on the association between posterior teeth occlusion necessary to maintain chewing function and cognitive function among older adults. This study examined the association between posterior teeth occlusion and cognitive function in nursing home older residents. In this cross-sectional study, 279 residents aged ≥60 years from eight nursing homes in Aso City, Japan participated in cognitive function and dental status assessments and completed a comprehensive questionnaire survey in 2014. Cognitive function was measured using a Mini-Mental State Examination (MMSE). Posterior teeth occlusion was assessed using a total number of functional tooth units (total-FTUs), depending on the number and location of the remaining natural and artificial teeth on implant-supported, fixed, and removable prostheses. Linear regression models were used to assess univariate and multivariate associations between total-FTUs and MMSE scores. Models were sequentially adjusted for demographic characteristics, number of natural teeth, socioeconomic status, health behaviors, comorbidities, physical function, and nutritional status. Among the 200 residents included in our analysis, mean MMSE scores and total-FTUs were 11.0 ± 8.6 and 9.3 ± 4.6, respectively. Higher total-FTUs were significantly associated with higher MMSE scores after adjustment for demographics and teeth number (B = 0.48, 95% confidence interval [CI] = 0.22–0.74). The association remained significant even after adjustment for all covariates (B = 0.25, 95% CI = 0.01–0.49). The current findings demonstrated that loss of posterior teeth occlusion was independently associated with cognitive decline in nursing home older residents in Japan. Maintenance and restoration of posterior teeth occlusion may be a preventive factor against cognitive decline in aged populations.