Oral flora in acute stroke patients: A prospective exploratory observational study

Temporal stability of tongue microbiota in older patients - A pilot study

Background/purpose

Healthy states of human microbiota depend on a stable community of symbiotic microbes irrespective of external challenges from the environment. Thus, long-term stability of the oral microbiota is of importance, particularly for older patient populations.

Materials and methods

We used next-generation sequencing (NGS) to examine the tongue microbiota of 18 individuals receiving long-term care over a 10-month period.

Results

Beta diversity analysis demonstrated temporal stability of the tongue microbiota, as microbial compositions from all time points were indistinguishable from each other (P = 0.0887). However, significant individual variation in microbial composition (P = 0.0001) was observed, underscoring the presence of a unique microbial profile for each patient.

Conclusion

The temporal dynamics of tongue microbiota exhibit long-term stability, providing diagnostic implications for oral diseases within older patient populations.

Association between oral microbial dysbiosis and poor functional outcomes in stroke-associated pneumonia patients

BACKGROUND

Despite advances in our understanding of the critical role of the microbiota in stroke patients, the oral microbiome has rarely been reported to be associated with stroke-associated pneumonia (SAP). We sought to profile the oral microbial composition of SAP patients and to determine whether microbiome temporal instability and special taxa are associated with pneumonia progression and functional outcomes.

METHODS

This is a prospective, observational, single-center cohort study that examined patients with acute ischemic stroke (AIS) who were admitted within 24 h of experiencing a stroke event. The patients were divided into three groups based on the occurrence of pneumonia and the use of mechanical ventilation: nonpneumonia group, SAP group, and ventilator-associated pneumonia (VAP) group. We collected oral swabs at different time points post-admission and analyzed the microbiota using 16 S rRNA high-throughput sequencing. The microbiota was then compared among the three groups.

RESULTS

In total, 104 nonpneumonia, 50 SAP and 10 VAP patients were included in the analysis. We found that SAP and VAP patients exhibited significant dynamic differences in the diversity and composition of the oral microbiota and that the magnitude of this dysbiosis and instability increased during hospitalization. Then, by controlling the potential effect of all latent confounding variables, we assessed the changes associated with pneumonia after stroke and explored patients with a lower abundance of Streptococcus were more likely to suffer from SAP. The logistic regression analysis revealed that an increase in specific taxa in the phylum Actinobacteriota was linked to a higher risk of poor outcomes. A model for SAP patients based on oral microbiota could accurately predict 30-day clinical outcomes after stroke onset.

CONCLUSIONS

We concluded that specific oral microbiota signatures could be used to predict illness development and clinical outcomes in SAP patients. We proposed the potential of the oral microbiota as a non-invasive diagnostic biomarker in the clinical management of SAP patients.

CLINICAL TRIAL REGISTRATION

NCT04688138. Registered 29/12/2020, https://clinicaltrials.gov/ct2/show/NCT04688138 .

Oral microbiome and ischemic stroke risk among elderly Chinese women

Background

Stroke, a leading cause of disability worldwide, has been associated with periodontitis. However, whether stroke risk is related to oral microbiota remains unknown. This study aims to evaluate the associations between the oral microbiome and ischemic stroke risk.

Methods

In a case-control study of 134 case-control pairs nested within a prospective cohort study, we examined pre-diagnostic oral microbiome in association with stroke risk via shotgun metagenomic sequencing. The microbial sub-community and functional profiling were performed using Latent Dirichlet Allocation and HUMAnN2. Associations of microbial diversity, sub-community structure, and individual microbial features with ischemic stroke risk were evaluated via conditional logistic regression.

Results

Alpha and beta diversities differ significantly between cases and controls. One genus- and two species-level sub-communities were significantly associated with decreased ischemic stroke risk, with odds ratios (95% confidence intervals) of 0.52 (0.31-0.90), 0.51 (0.31-0.84), and 0.60 (0.36-0.99), respectively. These associations were potentially driven by the representative taxa in these sub-communities, i.e., genus Corynebacterium and Lautropia, and species Lautropia mirabilis and Neisseria elongate (p < 0.05). Additionally, 55 taxa, 1,237 gene families, and 90 metabolic pathways were associated with ischemic stroke risk at p < 0.05.

Conclusion

Our study highlights the role of oral microbiota in the etiology of ischemic stroke and calls for further research.

Gastrointestinal Dysfunction in Stroke

Gastrointestinal (GI) complications are seen in over 50% of ischemic stroke survivors; the most common complications are dysphagia, constipation, and GI bleeding. The bidirectional relationship of the gut-brain axis and stroke has recently gained traction, wherein stroke contributes to gut dysbiosis (alterations in the normal host intestinal microbiome) and gut dysbiosis perpetuates poor functional neurologic outcomes in stroke. It is postulated that the propagation of proinflammatory cells and gut metabolites (including trimethylamine N-oxide and short-chain fatty acids) from the GI tract to the central nervous system play a central role in gut-brain axis dysfunction. In this review, we discuss the known GI complications in acute ischemic stroke, our current knowledge from experimental stroke models for gut-brain axis dysfunction in stroke, and emerging therapeutics that target the gut-brain axis.

Potential biomarker proteins for aspiration pneumonia detected by shotgun proteomics using buccal mucosa samples: a cross-sectional case-control study

BACKGROUND

Aspiration pneumonia (AP), which is a major cause of death in the elderly, does present with typical symptoms in the early stages of onset, thus it is difficult to detect and treat at an early stage. In this study, we identified biomarkers that are useful for the detection of AP and focused on salivary proteins, which may be collected non-invasively. Because expectorating saliva is often difficult for elderly people, we collected salivary proteins from the buccal mucosa.

METHODS

We collected samples from the buccal mucosa of six patients with AP and six control patients (no AP) in an acute-care hospital. Following protein precipitation using trichloroacetic acid and washing with acetone, the samples were analyzed by liquid chromatography and tandem mass spectrometry (LC-MS/MS). We also determined the levels of cytokines and chemokines in non-precipitated samples from buccal mucosa.

RESULTS

Comparative quantitative analysis of LC-MS/MS spectra revealed 55 highly (P values < 0.10) abundant proteins with high FDR confidence (q values < 0.01) and high coverage (> 50%) in the AP group compared with the control group. Among the 55 proteins, the protein abundances of four proteins (protein S100-A7A, eukaryotic translation initiation factor 1, Serpin B4, and peptidoglycan recognition protein 1) in the AP group showed a negative correlation with the time post-onset; these proteins are promising AP biomarker candidates. In addition, the abundance of C-reactive protein (CRP) in oral samples was highly correlated with serum CRP levels, suggesting that oral CRP levels may be used as a surrogate to predict serum CRP in AP patients. A multiplex cytokine/chemokine assay revealed that MCP-1 tended to be low, indicating unresponsiveness of MCP-1 and its downstream immune pathways in AP.

CONCLUSION

Our findings suggest that oral salivary proteins, which are obtained non-invasively, can be utilized for the detection of AP.

The oral microbiome of patients with ischemic stroke predicts their severity and prognosis

Background and objectives

Stroke is a common group of cerebrovascular diseases that can lead to brain damage or death. Several studies have shown a close link between oral health and stroke. However, the oral microbiome profiling of ischemic stroke (IS) and its potential clinical implication are unclear. This study aimed to describe the oral microbiota composition of IS, the high risk of IS, and healthy individuals and to profile the relationship between microbiota and IS prognosis.

Methods

This observational study recruited three groups: IS, high-risk IS (HRIS), and healthy control (HC) individuals. Clinical data and saliva were collected from participants. The modified Rankin scale score after 90 days was used to assess the prognosis of stroke. Extracted DNA from saliva and performed 16S ribosomal ribonucleic acid (rRNA) gene amplicon sequencing. Sequence data were analyzed using QIIME2 and R packages to evaluate the association between the oral microbiome and stroke.

Results

A total of 146 subjects were enrolled in this study according to the inclusion criteria. Compared with HC, HRIS and IS demonstrated a progressive increase trend in Chao1, observed species richness, and Shannon and Simpson diversity index. On the basis of permutational multivariate analysis of variance, the data indicate a great variation in the saliva microbiota composition between HC and HRIS (F = 2.40, P < 0.001), HC and IS (F = 5.07, P < 0.001), and HRIS and IS (F = 2.79, P < 0.001). The relative abundance of g_Streptococcus, g_Prevotella, g_Veillonella, g_Fusobacterium, and g_Treponema was higher in HRIS and IS compared with that in HC. Furthermore, we constructed the predictive model by differential genera to effectively distinguish patients with IS with poor 90-day prognoses from those with good (area under the curve = 79.7%; 95% CI, 64.41%-94.97%; p < 0.01).

Discussion

In summary, the oral salivary microbiome of HRIS and IS subjects have a higher diversity, and the differential bacteria have some predictive value for the severity and prognosis of IS. Oral microbiota may be used as potential biomarkers in patients with IS.

The role of the oral microbiome in smoking-related cardiovascular risk: a review of the literature exploring mechanisms and pathways

Cardiovascular disease is a leading cause of morbidity and mortality. Oral health is associated with smoking and cardiovascular outcomes, but there are gaps in knowledge of many mechanisms connecting smoking to cardiovascular risk. Therefore, the aim of this review is to synthesize literature on smoking and the oral microbiome, and smoking and cardiovascular risk/disease, respectively. A secondary aim is to identify common associations between the oral microbiome and cardiovascular risk/disease to smoking, respectively, to identify potential shared oral microbiome-associated mechanisms. We identified several oral bacteria across varying studies that were associated with smoking. Atopobium, Gemella, Megasphaera, Mycoplasma, Porphyromonas, Prevotella, Rothia, Treponema, and Veillonella were increased, while Bergeyella, Haemophilus, Lautropia, and Neisseria were decreased in the oral microbiome of smokers versus non-smokers. Several bacteria that were increased in the oral microbiome of smokers were also positively associated with cardiovascular outcomes including Porphyromonas, Prevotella, Treponema, and Veillonella. We review possible mechanisms that may link the oral microbiome to smoking and cardiovascular risk including inflammation, modulation of amino acids and lipids, and nitric oxide modulation. Our hope is this review will inform future research targeting the microbiome and smoking-related cardiovascular disease so possible microbial targets for cardiovascular risk reduction can be identified.

The Influence of Periodontal Diseases and the Stimulation of Saliva Secretion on the Course of the Acute Phase of Ischemic Stroke

Background and purpose: The course of an ischemic stroke depends on many factors. The influence of periodontal diseases and the stimulation of salivation on the course and severity of stroke remains unresolved. Therefore, the aim of the study was to analyze the severity of ischemic stroke depending on the occurrence of periodontal diseases and saliva stimulation. Methods: The severity of the neurological condition was assessed using the NIHSS scale on days one, three and seven of stroke. The incidence of periodontal diseases was classified using the Hall’s scale in the first day of stroke. On days one and seven of stroke, the concentration of IL-1β, MMP-8, OPG and RANKL in the patients’ saliva was assessed using the Elisa technique. At the same time, the level of CRP and the number of leukocytes in the peripheral blood were tested on days one, three and seven of the stroke, and the incidence of upper respiratory and urinary tract infections was assessed. Results:100 consecutive patients with their first ever ischemic stroke were enrolled in the study. 56 randomly selected patients were subjected to the stimulation of salivation, the remaining patients were not stimulated. In the study of the severity of the neurological condition using the NIHS scale on days three and seven of stroke, the degree of deficit in patients without periodontal disease significantly improved compared to patients with periodontal disease, respectively (p < 0.01 and p = 0.01). Patients from the stimulated group had more severe neurological deficit at baseline (p = 0.04). On days three and seven of neurological follow-up, the condition of patients from both groups improved with a further distinct advantage of the unstimulated group over the stimulated group, respectively (p = 0.03 and p < 0.001). In patients from both groups, a statistically significant decrease in CRP and lymphocyte levels was observed on day seven in relation to day one. Conclusions: The occurrence of periodontal disease in a patient with stroke affects the severity of stroke. Stimulation of the mouth and salivary glands in these patients may have a positive effect on the course of stroke, taking into account the dynamics of neurological symptoms.

Microbiology and Outcomes of Institutionalized Patients With Stroke-Associated Pneumonia: An Observational Cohort Study

Background: The attributable mortality and microbial etiology of stroke-associated pneumonia (SAP) vary among different studies and were inconsistent. Purpose: To determine the microbiology and outcomes of SAP in the lower respiratory tract (LRT) for patients with invasive mechanical ventilation (MV). Methods: In this observational study, included patients were divided into SAP and non-SAP based on a comprehensive analysis of symptom, imaging, and laboratory results. Baseline characteristics, clinical characteristics, microbiology, and outcomes were recorded and evaluated. Results: Of 200 patients, 42.5% developed SAP after the onset of stroke, and they had a lower proportion of non-smokers (p = 0.002), lower GCS score (p < 0.001), higher serum CRP (p < 0.001) at ICU admission, and a higher proportion of males (p < 0.001) and hypertension (p = 0.039) than patients with non-SAP. Gram-negative aerobic bacilli were the predominant organisms isolated (78.8%), followed by Gram-positive aerobic cocci (29.4%). The main pathogens included K. pneumoniae, S. aureus, H. influenzae, A. baumannii, P. aeruginosa, E. aerogenes, Serratia marcescens, and Burkholderia cepacia. SAP prolonged length of MV (p < 0.001), duration of ICU stay (p < 0.001) and hospital stay (p = 0.027), shortened MV-free days by 28 (p < 0.001), and caused elevated vasopressor application (p = 0.001) and 60-day mortality (p = 0.001). Logistic regression analysis suggested that patients with coma (p < 0.001) have a higher risk of developing SAP. Conclusion: The microbiology of SAP is similar to early phase of HAP and VAP. SAP prolongs the duration of MV and length of ICU and hospital stays, but also markedly increases 60-day mortality.

Pathogenic oral bacteria in hospitalised patients with dysphagia: The silent epidemic

Background

Aspiration pneumonia is a serious and fatal complication of dysphagia, secondary to the ingestion of bacteria-laden secretions. However, no studies have documented the oral hygiene features present in patients who present with dysphagia.

Objectives

The purpose of this study was to describe the oral hygiene problems of adults admitted to a sub-acute rehabilitation hospital and who presented with dysphagia.

Methods

A descriptive, cross-sectional survey was conducted, during which 40 participants – 57.5% (n = 23) male and 42.5% (n = 17) female – underwent a clinical swallow evaluation using the Mann Assessment of Swallowing Ability (MASA) augmented with cervical auscultation (CA) and pulse oximetry (PO), an oral hygiene assessment using an adapted version of the Oral Health Assessment Tool (OHAT), followed by microbiology laboratory analysis of buccal swab samples to detect bacteria not considered part of the normal oral flora.

Results

Results indicated that poor oral hygiene status was a common feature amongst all participants who presented with dysphagia. The most prevalent oral hygiene issues were related to abnormalities concerning saliva (60%), oral cleanliness (82.5%), the tongue (80%) and the use of dentures (71.4%). A high prevalence, 62.5% (n = 25), of opportunistic bacteria was found. The most commonly occurring bacteria groups were: (1) Candida albicans (47.5%) and (2) respiratory pathogens (37.5%) such as Klebsiella pneumoniae and Staphylococcus aureus.

Conclusion

Persons with dysphagia have poor oral hygiene which creates favourable environments for bacteria to flourish and increases the prevalence of pathogenic oral bacteria associated with the development of aspiration pneumonia. The management of oral health issues for persons with dysphagia should receive greater attention during hospitalisation.

Characteristics of aspiration pneumonia patients in acute care hospitals: A multicenter, retrospective survey in Northern Japan

BACKGROUND

Pneumonia is a common cause of illness and death of the elderly in Japan. Its prevalence is escalating globally with the aging of population. To describe the latest trends in pneumonia hospitalizations, especially aspiration pneumonia (AP) cases, we assessed the clinical records of pneumonia patients admitted to core acute care hospitals in Miyagi prefecture, Japan.

METHODS

A retrospective multi-institutional joint research was conducted for hospitalized pneumonia patients aged ≥20 years from January 2019 to December 2019. Clinical data of patients were collected from the medical records of eight acute care hospitals.

RESULTS

Out of the 1,800 patients included in this study, 79% of the hospitalized pneumonia patients were aged above 70 years. The most common age group was in the 80s. The ratio of AP to total pneumonia cases increased with age, and 692 out of 1,800 patients had AP. In univariate analysis, these patients had significantly older ages, lower body mass index (BMI), a lower ratio of normal diet intake and homestay before hospitalization, along with more AP recurrences and comorbidities. During hospitalization, AP patients had extended fasting periods, more swallowing assessments and interventions, longer hospitalization, and higher in-hospital mortality rate than non-AP patients. A total of 7% and 2% AP patients underwent video endoscopy and video fluorography respectively. In multivariate analysis, lower BMI, lower C-reactive protein, a lower ratio of homestay before hospitalization, a higher complication rate of cerebrovascular disease, dementia, and neuromuscular disease were noted as a characteristic of AP patients. Swallowing interventions were performed for 51% of the AP patients who had been hospitalized for more than two weeks. In univariate analysis, swallowing intervention improved in-hospital mortality. Lower AP recurrence before hospitalization and a lower ratio of homestay before hospitalization were indicated as characteristics of AP patients of the swallowing intervention group from multivariate analysis. Change in dietary pattern from normal to modified diet was observed more frequently in the swallowing intervention group.

CONCLUSION

AP accounts for 38.4% of all pneumonia cases in acute care hospitals in Northern Japan. The use of swallowing evaluations and interventions, which may reduce the risk of dysphagia and may associate with lowering mortality in AP patients, is still not widespread.

Microbiota Gut-Brain Axis in Ischemic Stroke: A Narrative Review with a Focus about the Relationship with Inflammatory Bowel Disease

The gut microbiota is emerging as an important player in neurodevelopment and aging as well as in brain diseases including stroke, Alzheimer’s disease, and Parkinson’s disease. The complex interplay between gut microbiota and the brain, and vice versa, has recently become not only the focus of neuroscience, but also the starting point for research regarding many diseases such as inflammatory bowel diseases (IBD). The bi-directional interaction between gut microbiota and the brain is not completely understood. The aim of this review is to sum up the evidencesconcerningthe role of the gut–brain microbiota axis in ischemic stroke and to highlight the more recent evidences about the potential role of the gut–brain microbiota axis in the interaction between inflammatory bowel disease and ischemic stroke.

The role of oral microbiome in respiratory health and diseases

The oral cavity (mouth) has various microbial habitats, including, teeth, gingival sulcus, gingiva, tongue, inner cheek, hard palate, and soft palate. The human oral cavity houses the second most diverse microbiome in the body harboring over 700 bacterial species. The fine-tuned equilibrium of the oral microbiome ecosystem maintains oral health. Oral dysbiosis caused by food habits and poor oral hygiene leads to various oral diseases such as periodontitis, caries, gingivitis, and oral cancer. Recent advances in technology have revealed the correlation between the oral microbiome and systemic diseases such as pulmonary diseases, cardiovascular diseases, rheumatoid arthritis, Alzheimer's disease, and other metabolic diseases. Since the oral cavity directly connects with the upper respiratory tract, the oral microbiome has easier access to the respiratory system compared to other organ systems. Direct aspiration of oral microflora in the respiratory system and oral dysbiosis-induced host immune reaction and inflammation are mainly responsible for various pulmonary complications. Numbers of literature have reported the correlation between oral diseases and pulmonary diseases, suggesting the possible role of the oral microbiome in respiratory diseases such as chronic obstructive pulmonary diseases, pneumonia, lung cancer, etc. This paper reviews the current evidence in establishing a link between the oral microbiome and pulmonary diseases. We also discuss future research directions focusing on the oral microbiome to unravel novel therapeutic approaches that could prevent or treat the various pulmonary complications.

Microbiome and ischemic stroke: A systematic review

Background

Ischemic stroke is one of the non-communicable diseases that contribute to the significant number of deaths worldwide. However, the relationship between microbiome and ischemic stroke remained unknown. Hence, the objective of this study was to perform systematic review on the relationship between human microbiome and ischemic stroke.

Methods

A systematic review on ischemic stroke was carried out for all articles obtained from databases until 22^nd October 2020. Main findings were extracted from all the eligible studies.

Results

Eighteen eligible studies were included in the systematic review. These studies suggested that aging, inflammation, and different microbial compositions could contribute to ischemic stroke. Phyla Firmicutes and Bacteroidetes also appeared to manipulate post-stroke outcome. The important role of microbiota-derived short-chain fatty acids and trimethylamine N-oxide in ischemic stroke were also highlighted.

Conclusions

This is the first systematic review that investigates the relationship between microbiome and ischemic stroke. Aging and inflammation contribute to differential microbial compositions and predispose individuals to ischemic stroke.

Oral Health, Oral Microbiota, and Incidence of Stroke-Associated Pneumonia-A Prospective Observational Study

Stroke-associated pneumonia is a major cause for poor outcomes in the post-acute phase after stroke. Several studies have suggested potential links between neglected oral health and pneumonia. Therefore, the aim of this prospective observational study was to investigate oral health and microbiota and incidence of pneumonia in patients consecutively admitted to a stroke unit with stroke-like symptoms. This study involved three investigation timepoints. The baseline investigation (within 24 h of admission) involved collection of demographic, neurological, and immunological data; dental examinations; and microbiological sampling (saliva and subgingival plaque). Further investigation timepoints at 48 or 120 h after baseline included collection of immunological data and microbiological sampling. Microbiological samples were analyzed by culture technique and by 16S rRNA amplicon sequencing. From the 99 patients included in this study, 57 were diagnosed with stroke and 42 were so-called stroke mimics. From 57 stroke patients, 8 (14%) developed pneumonia. Stroke-associated pneumonia was significantly associated with higher age, dysphagia, greater stroke severity, embolectomy, nasogastric tubes, and higher baseline C-reactive protein (CRP). There were trends toward higher incidence of pneumonia in patients with more missing teeth and worse oral hygiene. Microbiological analyses showed no relevant differences regarding microbial composition between the groups. However, there was a significant ecological shift over time in the pneumonia patients, probably due to antibiotic treatment. This prospective observational study investigating associations between neglected oral health and incidence of SAP encourages investigations in larger patient cohorts and implementation of oral hygiene programs in stroke units that may help reducing the incidence of stroke-associated pneumonia.

Intensified Oral Hygiene Care in Stroke-Associated Pneumonia: A Pilot Single-Blind Randomized Controlled Trial

In this pilot, single-blind, randomized controlled trial, we investigated the effects of intensified oral hygiene care (IOHC) on reducing stroke-associated pneumonia (SAP) incidence. Patients admitted within 24 hours of stroke onset were recruited and randomized to receive IOHC or routine oral hygiene care. The occurrence of SAP was checked and oral swabs were obtained during the 7-day follow-up. The SAP incidence was lower, though not significantly, in the IOHC group than in the control group. IOHC successfully decreased SAP incidence among patients who were male, had higher National Institutes of Health Stroke Scale and Debris Index scores, and lower Glasgow Coma Scale and Gugging Swallowing Screen scores. Furthermore, IOHC significantly decreased the prevalence of oral suspected SAP pathogens. These results suggest that IOHC can decrease the incidence of SAP in the most vulnerable patient groups and lower the prevalence of suspected oral SAP pathogens.

[Pulmonary insufficiency in acute stroke: risk factors and mechanisms of development]

Various degrees of pulmonary insufficiency (PI) (PaO₂ ≤60 mm Hg, SaO₂ ≤90%) are diagnosed in most of patients with severe acute stroke (AS). Frequency and severity of PI positively correlates with the severity of AS. PI worsens patient's condition, prolongs the hospitalization period, and increases the probability of fatal outcome. Early clinical signs of PI may be undiagnosed due to the severity of stroke and thus not treated. The initiating pathogenic mechanism of PI is stress-related activation of sympathetic nervous system (SNS) and systemic immunosuppression. In severe stroke with mass effect, the rapid and significant increase in intracranial pressure may additionally activate the SNS. Risk factors of PI include older age, previous pulmonary disease, prolonged supine position, respiratory muscle dysfunction, apnea, and concomitant somatic diseases. Decompensation of somatic diseases leads to multiple stage reactions with facilitation of functional and morphologic changes in the pulmonary system, hypoxemia and hypoxia, promotes infectious complications and multiple organ failure and worsens neurological outcome. Diagnosis and treatment of PI in AS decreases mortality and improves rehabilitation prognosis.

Factors associated with the number of microorganisms on the tongue surface in patients following acute stroke

BACKGROUND

Oral hygiene management of patients with acute stroke is important for preventing aspiration pneumonia and ensuring oral intake. The tongue coating score can be useful for evaluating the oral hygiene level since it reflects the microorganism number on the tongue surface in elderly patients. However, the relationship between the number of oral microorganisms and the tongue coating score in patients with acute stroke remains unclear.

OBJECTIVES

We aimed to investigate the relationships between the microorganism number on the tongue surface and oral factors, including tongue coating score, tongue surface moisture level and tongue function.

METHODS

This cross-sectional study enrolled 73 patients with acute stroke who were hospitalised at an acute care hospital and underwent dental intervention. Potential explanatory factors, including sex, age, Glasgow Coma Scale score, tongue coating score, tongue surface moisture level, nutrition intake method, number of functional teeth and tongue function, were evaluated. Logistic regression analysis determined their association with the microorganism number on the tongue surface.

RESULTS

The tongue coating score (odds ratio: 1.31) and tongue surface moisture level (odds ratio: 1.10) were significantly associated with increased microorganism numbers on the tongue surface.

CONCLUSION

The tongue coating score, which reflects the actual number of microorganisms on the tongue surface, could be an effective tool for evaluating oral hygiene level in patients with stroke. Moreover, reducing oral microorganisms in saliva through oral hygiene management, including removing the tongue coating, could contribute towards the prevention of aspiration pneumonia.

Deep DNA metagenomic sequencing reveals oral microbiome divergence between monozygotic twins discordant for multiple sclerosis severity

In contrast to gut, the oral microbiome of MS patients has not been characterized. Deep sequencing of saliva DNA from a pair of monozygotic twins (MSF1 with relapsing remitting MS; MSF2 with clinically isolated syndrome) identified 2036 bacterial species. Relative abundances of 3 phyla were higher, and 3 lower in MSF1 versus MSF2. Species diversity was greater in MSF2, and 20 abundant species differed at least 2-fold. Pathway analysis identified 116 functional hierarchies differing 50% or more. Although limited to one pair of twins, our data suggests that oral microbiome analysis may be useful for diagnosis or monitoring therapeutic efficacy.

Introducing an oral care assessment tool with advanced cleaning products into a high-risk clinical setting

Poor oral hygiene is an important risk factor for the development of non-ventilator hospital-associated pneumonia (NV-HAP), which imposes a significant burden on the NHS. This study aimed to establish whether the use of a 24-hour oral care kit and an oral care assessment tool can meet the needs of patients on an acute stroke unit. In comparison with the same period the preceding year, the introduction of the oral care kit and assessment tool improved compliance with oral care by more than 4 times; the overall costs of antibiotics to treat NV-HAP patients fell by 79%, with the number of doses falling by 70%, and the mortality rate decreased from 27% to 20%. According to a survey of multidisciplinary team (MDT) members keeping oral care tools available at the point of use saved time, and the oral health of patients on the unit improved after the introduction of the oral care kit and assessment tool. Almost all MDT members would recommend the use of the kit over previous interventions.

Exploring the microbiota of upper respiratory tract during the development of pneumonia in a mouse model

The alteration of the microbial community in the upper respiratory tract (URT) can contribute to the colonization and invasion of respiratory pathogens. However, there are no studies regarding whether the characteristics of the URT microbiota can be affected by infections in lower respiratory tract (LRT). To elucidate the microbial profiles of the URT during pneumonia, the oral, nasal, and lung microbiota was evaluated at the early phase in a murine pneumonia model by direct intratracheal inoculation of Klebsiella pneumoniae. The meta 16S rRNA sequencing of bronchoalveolar lavage fluid after K. pneumoniae inoculation presented alterations in the beta diversity of the microbes, but not in the alpha diversity. At this point, a significant increase in microbial alpha diversity was observed in the oral cavity, but not in the nasal cavity. The significant increase was observed in the family Carnobacteriaceae and family Enterococcaceae. These results suggest that characterizing the microbial community of the respiratory tract may not just involve a simple downstream relationship from the URT to the LRT. The health status of the LRT may influence the oral microbiota. Thus, evaluation of the oral microbiota may contribute towards monitoring lung health; the oral microbiota may act as a diagnostic marker of pneumonia.

Oral care after stroke: Where are we now?

Purpose

There appears to be an association between poor oral hygiene and increased risk of aspiration pneumonia - a leading cause of mortality post-stroke. We aim to synthesise what is known about oral care after stroke, identify knowledge gaps and outline priorities for research that will provide evidence to inform best practice.

Methods

A narrative review from a multidisciplinary perspective, drawing on evidence from systematic reviews, literature, expert and lay opinion to scrutinise current practice in oral care after a stroke and seek consensus on research priorities.Findings: Oral care tends to be of poor quality and delegated to the least qualified members of the caring team. Nursing staff often work in a pressured environment where other aspects of clinical care take priority. Guidelines that exist are based on weak evidence and lack detail about how best to provide oral care.

Discussion

Oral health after a stroke is important from a social as well as physical health perspective, yet tends to be neglected. Multidisciplinary research is needed to improve understanding of the complexities associated with delivering good oral care for stroke patients. Also to provide the evidence for practice that will improve wellbeing and may reduce risk of aspiration pneumonia and other serious sequelae.

Conclusion

Although there is evidence of an association, there is only weak evidence about whether improving oral care reduces risk of pneumonia or mortality after a stroke. Clinically relevant, feasible, cost-effective, evidence-based oral care interventions to improve patient outcomes in stroke care are urgently needed.