Analysis of Salivary Microbiome in Patients with Alzheimer's Disease

From BugSigDB
Needs review
study design
Citation
PMID PubMed identifier for scientific articles.
DOI Digital object identifier for electronic documents.
URI
Authors
Liu XX, Jiao B, Liao XX, Guo LN, Yuan ZH, Wang X, Xiao XW, Zhang XY, Tang BS, Shen L
Journal
Journal of Alzheimer's disease : JAD
Year
2019
Keywords:
16S rRNA, APOE, Alzheimer’s disease, oral microbiome
Recent studies found that poor oral hygiene was associated with increased risk of dementia, and the number of oral bacteria significantly increased in the brain tissues of patients with Alzheimer's disease (AD), suggesting that the oral microbiota may play an important role in the pathogenesis of AD. However, the actual composition of oral bacteria communities in patients with AD and whether these oral bacteria are associated with disease severity remain largely unknown. Also, the APOEɛ4 polymorphism is a strong risk factor for sporadic AD, and it would be pertinent to see if the bacterial flora was different in those patients who were APOEɛ4 positive. A total of 78 subjects were recruited in this study, including 39 patients with AD and 39 healthy controls. Saliva was collected from each subject. 16S ribosomal RNA (16S rRNA) sequencing was conducted to analyze the salivary microbiota, and Sanger sequencing was performed to analyze the APOE genotype. There was a significantly lower richness and diversity of saliva microbiota detected in AD patients than healthy controls. The relative abundance of Moraxella, Leptotrichia, and Sphaerochaeta in the saliva of AD patients greatly increased, whereas that of Rothia was significantly reduced. Compared with APOEɛ4 (-) patients, the level of Abiotrophia and Desulfomicrobium was comparatively abundant, while Actinobacillus and Actinomyces decreased significantly in patients carrying the APOEɛ4. No bacteria were found to be associated with the severity of AD. This is the first study to analyze the salivary microorganisms in patients with AD, and we discovered that the composition of salivary microbiome was altered in AD, providing further support for the role of the oral microbiome in AD development.

Experiment 1


Needs review

Curated date: 2024/12/01

Curator: AaishahM

Revision editor(s): AaishahM

Subjects

Location of subjects
China
Host species Species from which microbiome was sampled. Contact us to have more species added.
Homo sapiens
Body site Anatomical site where microbial samples were extracted from according to the Uber Anatomy Ontology
Saliva Sailva normalis,Saliva atomaris,Saliva molecularis,Salivary gland secretion,Saliva,saliva
Condition The experimental condition / phenotype studied according to the Experimental Factor Ontology
Alzheimer's disease [X]Dementia in Alzheimer's disease,[X]Dementia in Alzheimer's disease (disorder),AD,AD - Alzheimer's disease,Alzheimer Dementia,Alzheimer dementia,Alzheimer Dementia, Presenile,ALZHEIMER DIS,Alzheimer Disease,Alzheimer disease,Alzheimer disease, familial,Alzheimer Type Dementia,Alzheimer's,Alzheimer's Dementia,Alzheimer's dementia,Alzheimer's disease,Alzheimer's disease (disorder),Alzheimer's disease, NOS,Alzheimers,Alzheimers Dementia,Alzheimers dementia,ALZHEIMERS DIS,Alzheimers disease,DAT - Dementia Alzheimer's type,Dementia in Alzheimer's disease,Dementia in Alzheimer's disease (disorder),Dementia in Alzheimer's disease, unspecified (disorder),Dementia of the Alzheimer's type,Dementia, Alzheimer Type,Dementia, Presenile,Dementia, Presenile Alzheimer,Disease, Alzheimer,Disease, Alzheimer's,Presenile Alzheimer Dementia,sporadic Alzheimer's disease,alzheimer's disease
Group 0 name Corresponds to the control (unexposed) group for case-control studies
Healthy controls
Group 1 name Corresponds to the case (exposed) group for case-control studies
Alzheimer's Disease (AD) patients
Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group
Patients with Alzheimer's Disease
Group 0 sample size Number of subjects in the control (unexposed) group
39
Group 1 sample size Number of subjects in the case (exposed) group
39
Antibiotics exclusion Number of days without antibiotics usage (if applicable) and other antibiotics-related criteria used to exclude participants (if any)
1 month

Lab analysis

Sequencing type
16S
16S variable region One or more hypervariable region(s) of the bacterial 16S gene
V3-V4
Sequencing platform Manufacturer and experimental platform used for quantifying microbial abundance
Illumina

Statistical Analysis

Data transformation Data transformation applied to microbial abundance measurements prior to differential abundance testing (if any).
relative abundances
Statistical test
T-Test
Significance threshold p-value or FDR threshold used for differential abundance testing (if any)
0.05
MHT correction Have statistical tests be corrected for multiple hypothesis testing (MHT)?
No

Alpha Diversity

Shannon Estimator of species richness and species evenness: more weight on species richness
decreased
Chao1 Abundance-based estimator of species richness
decreased
Richness Number of species
decreased

Signature 1

Needs review

Curated date: 2024/12/01

Curator: AaishahM

Revision editor(s): AaishahM

Source: Figure 2

Description: Relative abundance of bacterial phyla

Abundance in Group 1: increased abundance in Alzheimer's Disease (AD) patients

NCBI Quality ControlLinks
Moraxella

Revision editor(s): AaishahM

Experiment 2


Needs review

Curated date: 2024/12/02

Curator: AaishahM

Revision editor(s): AaishahM

Differences from previous experiment shown

Subjects

Group 0 name Corresponds to the control (unexposed) group for case-control studies
APOE ε4(-)
Group 1 name Corresponds to the case (exposed) group for case-control studies
APOE ε4(+)
Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group
Patients who are APOE ε4 positive
Group 0 sample size Number of subjects in the control (unexposed) group
16
Group 1 sample size Number of subjects in the case (exposed) group
23

Lab analysis

Statistical Analysis

Statistical test
Metastats

Alpha Diversity

Shannon Estimator of species richness and species evenness: more weight on species richness
decreased
Chao1 Abundance-based estimator of species richness
decreased
Richness Number of species
decreased

Signature 1

Needs review

Curated date: 2024/12/02

Curator: AaishahM

Revision editor(s): AaishahM

Source: Figure 3

Description: Metastats analysis of taxa in AD patients with different APOE phenotype

Abundance in Group 1: decreased abundance in APOE ε4(+)

NCBI Quality ControlLinks
Actinomycetaceae
Actinomyces
Actinobacillus

Revision editor(s): AaishahM

Experiment 3


Needs review

Curated date: 2024/12/02

Curator: AaishahM

Revision editor(s): AaishahM

Differences from previous experiment shown

Subjects

Group 0 name Corresponds to the control (unexposed) group for case-control studies
Healthy controls
Group 1 name Corresponds to the case (exposed) group for case-control studies
Alzheimer's Disease (AD) patients
Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group
Patients with Alzheimer's Disease
Group 0 sample size Number of subjects in the control (unexposed) group
39
Group 1 sample size Number of subjects in the case (exposed) group
39

Lab analysis

Statistical Analysis

Statistical test
LEfSe
LDA Score above Threshold for the linear discriminant analysis (LDA) score for studies using the popular LEfSe tool
2.0

Alpha Diversity

Shannon Estimator of species richness and species evenness: more weight on species richness
decreased
Chao1 Abundance-based estimator of species richness
decreased
Richness Number of species
decreased

Signature 1

Needs review

Curated date: 2024/12/02

Curator: AaishahM

Revision editor(s): AaishahM

Source: Figure 4A + Figure 4B

Description: LEfSe results on saliva microbiome

Abundance in Group 1: increased abundance in Alzheimer's Disease (AD) patients

NCBI Quality ControlLinks
Gemella
Kingella
Leptotrichia
Mogibacterium
Moraxella
Sphaerochaeta
Leptotrichiaceae
Eubacteriaceae
SphaerochaetalesSphaerochaetales
SphaerochaetaceaeSphaerochaetaceae
BD1_5BD1_5

Revision editor(s): AaishahM

Signature 2

Needs review

Curated date: 2024/12/02

Curator: AaishahM

Revision editor(s): AaishahM

Source: Figure 4A + Figure 4B

Description: LEfSe results on saliva microbiome

Abundance in Group 1: decreased abundance in Alzheimer's Disease (AD) patients

NCBI Quality ControlLinks
Rothia
Actinomycetota
Actinomycetales
Micrococcaceae
OtherOther

Revision editor(s): AaishahM

Experiment 4


Needs review

Curated date: 2024/12/02

Curator: AaishahM

Revision editor(s): AaishahM

Differences from previous experiment shown

Subjects

Group 0 name Corresponds to the control (unexposed) group for case-control studies
APOE ε4(-)
Group 1 name Corresponds to the case (exposed) group for case-control studies
APOE ε4(+)
Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group
Patients who are APOE ε4 positive
Group 0 sample size Number of subjects in the control (unexposed) group
16
Group 1 sample size Number of subjects in the case (exposed) group
23

Lab analysis

Statistical Analysis

Alpha Diversity

Shannon Estimator of species richness and species evenness: more weight on species richness
decreased
Chao1 Abundance-based estimator of species richness
decreased
Richness Number of species
decreased

Signature 1

Needs review

Curated date: 2024/12/02

Curator: AaishahM

Revision editor(s): AaishahM

Source: Figure 4C + Figure 4D

Description: LEfSe results on saliva microbiome

Abundance in Group 1: increased abundance in APOE ε4(+)

NCBI Quality ControlLinks
Abiotrophia
Aerococcaceae
Desulfomicrobium

Revision editor(s): AaishahM

Signature 2

Needs review

Curated date: 2024/12/02

Curator: AaishahM

Revision editor(s): AaishahM

Source: Figure 4C

Description: LEfSe results on saliva microbiome

Abundance in Group 1: decreased abundance in APOE ε4(+)

NCBI Quality ControlLinks
Actinobacillus

Revision editor(s): AaishahM