Oral Dysbiosis and Inflammation in Parkinson’s Disease

Background: Oral microbiota has largely escaped attention in Parkinson’s disease (PD), despite its pivotal role in maintaining oral and systemic health. Objective: The aim of our study was to examine the composition of the oral microbiota and the degree of oral inflammation in PD. Methods: Twenty PD patients were compared to 20 healthy controls. Neurological, periodontal and dental examinations were performed as well as dental scaling and gingival crevicular fluid sampling for cytokines measurement (interleukine (IL)-1β, IL-6, IL-1 receptor antagonist (RA), interferon-γ and tumor necrosis factor (TNF)-α). Two months later, oral microbiota was sampled from saliva and subgingival dental plaque. A 16S rRNA gene amplicon sequencing was used to assess bacterial communities. Results: PD patients were in the early and mid-stage phases of their disease (Hoehn & Yahr 2–2.5). Dental and periodontal parameters did not differ between groups. The levels of IL-1β and IL-1RA were significantly increased in patients compared to controls with a trend for an increased level of TNF-α in patients. Both saliva and subgingival dental plaque microbiota differed between patients and controls. Streptococcus mutans, Kingella oralis, Actinomyces AFQC_s, Veillonella AFUJ_s, Scardovia, Lactobacillaceae, Negativicutes and Firmicutes were more abundant in patients, whereas Treponema KE332528_s, Lachnospiraceae AM420052_s, and phylum SR1 were less abundant. Conclusion: Our findings show that the oral microbiome is altered in early and mid-stage PD. Although PD patients had good dental and periodontal status, local inflammation was already present in the oral cavity. The relationship between oral dysbiosis, inflammation and the pathogenesis of PD requires further study.

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The Role of the Western Diet and Oral Microbiota in Parkinson’s Disease

Nutrients ◽

10.3390/nu14020355 ◽

2022 ◽

Vol 14 (2) ◽

pp. 355

Author(s):

Barbara Zapała ◽

Tomasz Stefura ◽

Tomasz Milewicz ◽

Julia Wątor ◽

Monika Piwowar ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Food Preferences ◽

Amplicon Sequencing ◽

Rrna Gene ◽

Oral Microbiota ◽

Healthy Controls ◽

Increased Risk ◽

Specific Food

The type of diet not only affects the composition of the oral microflora but is also one of the more critical factors associated with an increased risk of Parkinson’s disease, PD. This study compared diet preferences and oral microbiota profiles in patients with PD vs. healthy controls. This study compared the oral microbiota composition of 59 patients with PD and 108 healthy controls (without neurodegeneration) using 16S rRNA gene amplicon sequencing. According to results, oral microbiota in patients with PD is different compared from healthy controls. In particular, decreased abundance of Proteobacteria, Pastescibacteria, and Tenercutes was observed. The oral cavity of patients with PD was characterized by the high relative abundance of bacteria from the genera Prevotella, Streptococcus, and Lactobaccillus. There were also differences in food preferences between patients with PD and healthy controls, which revealed significantly higher intake of margarine, fish, red meat, cereals products, avocado, and olives in the patients with PD relative to healthy controls. Strong positive and negative correlations between specific food products and microbial taxa were identified.

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Oral Microbiota Identifies Patients in Early Onset Rheumatoid Arthritis

Microorganisms ◽

10.3390/microorganisms9081657 ◽

2021 ◽

Vol 9 (8) ◽

pp. 1657

Author(s):

Anders Esberg ◽

Linda Johansson ◽

Ingegerd Johansson ◽

Solbritt Rantapää Dahlqvist

Keyword(s):

Rheumatoid Arthritis ◽

Early Onset ◽

Amplicon Sequencing ◽

Oral Bacteria ◽

Oral Microbiome ◽

Rrna Gene ◽

Oral Microbiota ◽

Disease Manifestation ◽

Periodontal Status ◽

Quality Register

Rheumatoid arthritis (RA) is the most common autoimmune inflammatory disease, and single periodontitis-associated bacteria have been suggested in disease manifestation. Here, the oral microbiota was characterized in relation to the early onset of RA (eRA) taking periodontal status into consideration. 16S rRNA gene amplicon sequencing of saliva bacterial DNA from 61 eRA patients without disease-modifying anti-rheumatic drugs and 59 matched controls was performed. Taxonomic classification at 98.5% was conducted against the Human Oral Microbiome Database, microbiota functions were predicted using PICRUSt, and periodontal status linked from the Swedish quality register for clinically assessed caries and periodontitis. The participants were classified into three distinct microbiota-based cluster groups with cluster allocation differences by eRA status. Independently of periodontal status, eRA patients had enriched levels of Prevotella pleuritidis, Treponema denticola, Porphyromonas endodontalis and Filifactor alocis species and in the Porphyromonas and Fusobacterium genera and functions linked to ornithine metabolism, glucosylceramidase, beta-lactamase resistance, biphenyl degradation, fatty acid metabolism and 17-beta-estradiol-17-dehydrogenase metabolism. The results support a deviating oral microbiota composition already in eRA patients compared with healthy controls and highlight a panel of oral bacteria that may be useful in eRA risk assessment in both periodontally healthy and diseased persons.

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Oral microbiota and dental caries data from monozygotic and dizygotic twin children

Scientific Data ◽

10.1038/s41597-020-00691-z ◽

2020 ◽

Vol 7 (1) ◽

Author(s):

Yelda Kasimoglu ◽

Mine Koruyucu ◽

Sinem Birant ◽

Ilker Karacan ◽

Nursen Topcuoglu ◽

...

Keyword(s):

Dental Caries ◽

16S Rrna ◽

Clinical Investigation ◽

Monozygotic Twins ◽

Amplicon Sequencing ◽

Oral Microbiome ◽

Rrna Gene ◽

Oral Microbiota ◽

Microbiome Profile ◽

Twin Children

Abstract There are recent studies which aimed to detect the inheritance on the etiology of dental caries exploring oral composition. We present data on the oral microbiota and its relation with dental caries and other factors in monozygotic (MZ) and dizygotic (DZ) twin children. Following clinical investigation, DNA samples were collected and isolated from saliva of 198 patients (49 MZ and 50 DZ twins) with an average age of 9.7 ± 2.7 years. Salivary bacterial microbiota analysis was performed using high throughput amplicon sequencing method targeting V3-V4 region of the 16S rRNA gene. A total of 8,297,859 raw reads corresponding to 41,908 reads per sample were obtained on average. The QIIME2-deblur workflow was used for 16S rRNA amplicon analysis. Microbiome similarity analyses between twins (based on Bray-Curtis dissimilarity, weighted and unweighted Unifrac distances) showed that monozygotic twins share more bacterial microbial content compared to dizygotic twins. This is a large microbial community dataset of MZ and DZ twins with or without dental findings which can be further used for children oral microbiome profile explorations.

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Deep nasal sinus cavity microbiota dysbiosis in Parkinson’s disease

npj Parkinson s Disease ◽

10.1038/s41531-021-00254-y ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Gian Pal ◽

Vivian Ramirez ◽

Phillip A. Engen ◽

Ankur Naqib ◽

Christopher B. Forsyth ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Olfactory Bulb ◽

Nasal Cavity ◽

Amplicon Sequencing ◽

Motor Symptom ◽

Rrna Gene ◽

Healthy Controls ◽

Nasal Sinus ◽

Severe Motor

AbstractOlfactory dysfunction is a pre-motor symptom of Parkinson’s disease (PD) that appears years prior to diagnosis and can affect quality of life in PD. Changes in microbiota community in deep nasal cavity near the olfactory bulb may trigger the olfactory bulb-mediated neuroinflammatory cascade and eventual dopamine loss in PD. To determine if the deep nasal cavity microbiota of PD is significantly altered in comparison to healthy controls, we characterized the microbiota of the deep nasal cavity using 16S rRNA gene amplicon sequencing in PD subjects and compared it to that of spousal and non-spousal healthy controls. Correlations between microbial taxa and PD symptom severity were also explored. Olfactory microbial communities of PD individuals were more similar to those of their spousal controls than to non-household controls. In direct comparison of PD and spousal controls and of PD and non-spousal controls, significantly differently abundant taxa were identified, and this included increased relative abundance of putative opportunistic-pathobiont species such as Moraxella catarrhalis. M. catarrhalis was also significantly correlated with more severe motor scores in PD subjects. This proof-of-concept study provides evidence that potential pathobionts are detected in the olfactory bulb and that a subset of changes in the PD microbiota community could be a consequence of unique environmental factors associated with PD living. We hypothesize that an altered deep nasal microbiota, characterized by a putative pro-inflammatory microbial community, could trigger neuroinflammation in PD.

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Storage media and not extraction method has the biggest impact on recovery of bacteria from the oral microbiome

Scientific Reports ◽

10.1038/s41598-019-51448-7 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Xiaoyan Zhou ◽

Shanika Nanayakkara ◽

Jin-Long Gao ◽

Ky-Anh Nguyen ◽

Christina J. Adler

Keyword(s):

Dna Extraction ◽

Dental Plaque ◽

Extraction Method ◽

Storage Conditions ◽

Oral Microbiome ◽

Rrna Gene ◽

Oral Microbiota ◽

Bead Beating ◽

Storage Media ◽

Dna Extraction Method

Abstract Next Generation sequencing has greatly progressed the exploration of the oral microbiome’s role in dental diseases, however, there has been little focus on the effect of sample storage conditions and their interaction with DNA extraction method. Dental plaque samples collected from 20 healthy participants were pooled and stored in either 75% ethanol or Bead solution for up to 6-months at −80 °C, prior to DNA extraction with either QIAamp (non-bead beating) or PowerSoil (bead-beating) kit, followed by Illumina sequencing of 16S rRNA gene. We found that storage media and not extraction method had the biggest influence on the diversity and abundance of the oral microbiota recovered. Samples stored in Bead solution, independent of the extraction kit, retrieved higher diversity (PowerSoil p = 1.64E-07, QIAamp p = 0.0085) and had dissimilar overall ecologies as indicated by lower level of shared diversity (PowerSoil p = 0.0000237, QIAamp p = 0.0088). Comparatively, samples stored in Bead solution and extracted with PowerSoil recovered a higher abundance of Streptococcus species. These data indicate that Bead solution can preserve the oral microbiome in dental plaque reliably, for periods of up to 6-months at −80 °C, and is compatible, with either a bead-beating or non-bead beating DNA extraction method.

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Much ado about nothing? Off-target amplification can lead to false-positive bacterial brain microbiome detection in healthy and Parkinson’s disease individuals

Microbiome ◽

10.1186/s40168-021-01012-1 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Janis R. Bedarf ◽

Naiara Beraza ◽

Hassan Khazneh ◽

Ezgi Özkurt ◽

David Baker ◽

...

Keyword(s):

Parkinson’S Disease ◽

16S Rrna ◽

16S Rrna Gene ◽

False Positive ◽

Gene Sequencing ◽

Bacterial Biomass ◽

16S Rrna Gene Sequencing ◽

Amplicon Sequencing ◽

Rrna Gene ◽

Rrna Gene Sequencing

Abstract Background Recent studies suggested the existence of (poly-)microbial infections in human brains. These have been described either as putative pathogens linked to the neuro-inflammatory changes seen in Parkinson’s disease (PD) and Alzheimer’s disease (AD) or as a “brain microbiome” in the context of healthy patients’ brain samples. Methods Using 16S rRNA gene sequencing, we tested the hypothesis that there is a bacterial brain microbiome. We evaluated brain samples from healthy human subjects and individuals suffering from PD (olfactory bulb and pre-frontal cortex), as well as murine brains. In line with state-of-the-art recommendations, we included several negative and positive controls in our analysis and estimated total bacterial biomass by 16S rRNA gene qPCR. Results Amplicon sequencing did detect bacterial signals in both human and murine samples, but estimated bacterial biomass was extremely low in all samples. Stringent reanalyses implied bacterial signals being explained by a combination of exogenous DNA contamination (54.8%) and false positive amplification of host DNA (34.2%, off-target amplicons). Several seemingly brain-enriched microbes in our dataset turned out to be false-positive signals upon closer examination. We identified off-target amplification as a major confounding factor in low-bacterial/high-host-DNA scenarios. These amplified human or mouse DNA sequences were clustered and falsely assigned to bacterial taxa in the majority of tested amplicon sequencing pipelines. Off-target amplicons seemed to be related to the tissue’s sterility and could also be found in independent brain 16S rRNA gene sequences. Conclusions Taxonomic signals obtained from (extremely) low biomass samples by 16S rRNA gene sequencing must be scrutinized closely to exclude the possibility of off-target amplifications, amplicons that can only appear enriched in biological samples, but are sometimes assigned to bacterial taxa. Sequences must be explicitly matched against any possible background genomes present in large quantities (i.e., the host genome). Using close scrutiny in our approach, we find no evidence supporting the hypothetical presence of either a brain microbiome or a bacterial infection in PD brains.

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Oral Factors That Impact the Oral Microbiota in Parkinson’s Disease

Microorganisms ◽

10.3390/microorganisms9081616 ◽

2021 ◽

Vol 9 (8) ◽

pp. 1616

Author(s):

Natalia S. Rozas ◽

Gena D. Tribble ◽

Cameron B. Jeter

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Oral Health ◽

Soft Tissue ◽

Oral Hygiene ◽

Beta Diversity ◽

Oral Microbiota ◽

Healthy Controls ◽

Microbiota Composition ◽

Salivary Ph

Patients with Parkinson’s disease (PD) are at increased risk of aspiration pneumonia, their primary cause of death. Their oral microbiota differs from healthy controls, exacerbating this risk. Our goal was to explore if poor oral health, poor oral hygiene, and dysphagia status affect the oral microbiota composition of these patients. In this cross-sectional case-control study, the oral microbiota from hard and soft tissues of patients with PD (n = 30) and age-, gender-, and education-matched healthy controls (n = 30) was compared using 16S rRNA gene sequencing for bacterial identification. Study participants completed dietary, oral hygiene, drooling, and dysphagia questionnaires, and an oral health screening. Significant differences in soft tissue beta-diversity (p < 0.005) were found, and a higher abundance of opportunistic oral pathogens was detected in patients with PD. Factors that significantly influenced soft tissue beta-diversity and microbiota composition include dysphagia, drooling (both p < 0.05), and salivary pH (p < 0.005). Thus, patients with PD show significant differences in their oral microbiota compared to the controls, which may be due, in part, to dysphagia, drooling, and salivary pH. Understanding factors that alter their oral microbiota could lead to the development of diagnostic and treatment strategies that improve the quality of life and survivability of these patients.

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OTUs clustering should be avoided for defining oral microbiome

10.1101/2021.08.09.455616 ◽

2021 ◽

Author(s):

Alba Regueira-Iglesias ◽

Lara Vazquez-Gonzalez ◽

Carlos Balsa-Castro ◽

Triana Blanco-Pintos ◽

Victor Manuel Arce ◽

...

Keyword(s):

Microbial Diversity ◽

Operational Taxonomic Unit ◽

Oral Bacteria ◽

Oral Microbiome ◽

Rrna Gene ◽

Oral Microbiota ◽

High Coverage ◽

Archaeal Species ◽

Health And Disease ◽

Similarity Relationships

This in silico investigation aimed to: 1) evaluate a set of primer pairs with high coverage, including those most commonly used in the literature, to find the different oral species with 16S rRNA gene amplicon similarity/identity (ASI) values ≥97%; and 2) identify oral species that may be erroneously clustered in the same operational taxonomic unit (OTU) and ascertain whether they belong to distinct genera or other higher taxonomic ranks. Thirty-nine primer pairs were employed to obtain amplicon sequence variants (ASVs) from the complete genomes of 186 bacterial and 135 archaeal species. For each primer, ASVs without mismatches were aligned using BLASTN and their similarity values were obtained. Finally, we selected ASVs from different species with an ASI value ≥97% that were covered 100% by the query sequences. For each primer, the percentage of species-level coverage with no ASI≥97% (SC-NASI≥97%) was calculated. Based on the SC-NASI≥97% values, the best primer pairs were OP_F053-KP_R020 for bacteria (65.05%), KP_F018-KP_R002 for archaea (51.11%), and OP_F114-KP_R031 for bacteria and archaea together (52.02%). Eighty percent of the oral-bacteria and oral-archaea species shared an ASI≥97% with at least one other taxa, including Campylobacter, Rothia, Streptococcus, and Tannerella, which played conflicting roles in the oral microbiota. Moreover, around a quarter and a third of these two-by-two similarity relationships were between species from different bacteria and archaea genera, respectively. Furthermore, even taxa from distinct families, orders, and classes could be grouped in the same cluster. Consequently, irrespective of the primer pair used, OTUs constructed with a 97% similarity provide an inaccurate description of oral-bacterial and oral-archaeal species, greatly affecting microbial diversity parameters. As a result, clustering by OTUs impacts the credibility of the associations between some oral species and certain health and disease conditions. This limits significantly the comparability of the microbial diversity findings reported in oral microbiome literature.

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Impact of Oropharyngeal Administration of Colostrum in Preterm Newborns’ Oral Microbiome

Nutrients ◽

10.3390/nu13124224 ◽

2021 ◽

Vol 13 (12) ◽

pp. 4224

Author(s):

Ramon V. Cortez ◽

Andrea Fernandes ◽

Luiz Gustavo Sparvoli ◽

Marina Padilha ◽

Rubens Feferbaum ◽

...

Keyword(s):

Preterm Infants ◽

16S Rrna Gene Sequencing ◽

Oral Microbiome ◽

Rrna Gene ◽

Oral Microbiota ◽

Alpha And Beta Diversity ◽

Longitudinal Observational Study ◽

Key Factor ◽

Rrna Gene Sequencing ◽

Preterm Newborns

The initial colonization of the human microbiota is of paramount importance. In this context, the oropharyngeal administration of colostrum is a safe, viable, and well-tolerated practice even by the smallest preterm infants. Therefore, this study evaluated the effects of oropharyngeal administration of colostrum on the establishment of preterm infants’ oral microbiota. A longitudinal observational study was carried out with 20 premature neonates, divided into two groups: one receiving the protocol (Oropharyngeal Administration of Colostrum; OAC) and the other one receiving Standard Caare (SC). Saliva samples were collected from the newborns weekly during the study period (from the day of birth until the 21st day of life) for analysis of oral microbiota through 16S rRNA gene sequencing. We observed that the colonization of the oral microbiota of preterm newborns preseanted a higher relative abundance of Staphylococcus on the 7th day of life, mainly in the OAC group. Additionally, an increased abundance of Bifidobacterium and Bacteroides was observed in the OAC group at the first week of life. Regarding alpha and beta diversity, time was a key factor in the oral modulation of both groups, showing how dynamic this environment is in early life.

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Human oral microbiome and prospective risk for pancreatic cancer: a population-based nested case-control study

Gut ◽

10.1136/gutjnl-2016-312580 ◽

2016 ◽

Vol 67 (1) ◽

pp. 120-127 ◽

Cited By ~ 177

Author(s):

Xiaozhou Fan ◽

Alexander V Alekseyenko ◽

Jing Wu ◽

Brandilyn A Peters ◽

Eric J Jacobs ◽

...

Keyword(s):

Pancreatic Cancer ◽

Case Control Study ◽

Case Control ◽

Oral Microbiome ◽

Rrna Gene ◽

Oral Microbiota ◽

Increased Risk ◽

Oral Pathogens ◽

Nested Case Control ◽

Control Study

ObjectiveA history of periodontal disease and the presence of circulating antibodies to selected oral pathogens have been associated with increased risk of pancreatic cancer; however, direct relationships of oral microbes with pancreatic cancer have not been evaluated in prospective studies. We examine the relationship of oral microbiota with subsequent risk of pancreatic cancer in a large nested case–control study.DesignWe selected 361 incident adenocarcinoma of pancreas and 371 matched controls from two prospective cohort studies, the American Cancer Society Cancer Prevention Study II and the National Cancer Institute Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. From pre-diagnostic oral wash samples, we characterised the composition of the oral microbiota using bacterial 16S ribosomal RNA (16S rRNA) gene sequencing. The associations between oral microbiota and risk of pancreatic cancer, controlling for the random effect of cohorts and other covariates, were examined using traditional and L1-penalised least absolute shrinkage and selection operator logistic regression.ResultsCarriage of oral pathogens, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, were associated with higher risk of pancreatic cancer (adjusted OR for presence vs absence=1.60 and 95% CI 1.15 to 2.22; OR=2.20 and 95% CI 1.16 to 4.18, respectively). Phylum Fusobacteria and its genus Leptotrichia were associated with decreased pancreatic cancer risk (OR per per cent increase of relative abundance=0.94 and 95% CI 0.89 to 0.99; OR=0.87 and 95% CI 0.79 to 0.95, respectively). Risks related to these phylotypes remained after exclusion of cases that developed within 2 years of sample collection, reducing the likelihood of reverse causation in this prospective study.ConclusionsThis study provides supportive evidence that oral microbiota may play a role in the aetiology of pancreatic cancer.

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