Objectives: It has been suggested that smoking affects the oral microbiome, but its effects on sites other than the subgingival microbiome remain unclear. This study investigated the composition of the salivary and tongue bacterial communities of smokers and nonsmokers in periodontally healthy adults.
Methods: The study population included 50 healthy adults. The bacterial composition of resting saliva and the tongue coating was identified through barcoded pyrosequencing analysis of the 16S rRNA gene. The Brinkman index (BI) was used to calculate lifetime exposure to smoking. The richness and diversity of the microbiome were evaluated using the t-test. Differences in the proportions of bacterial genera between smokers and nonsmokers were evaluated using the Mann-Whitney U test. The quantitative relationship between the proportions of genera and the BI was evaluated using Pearson's correlation analysis.
Results: The richness and diversity of the oral microbiome differed significantly between saliva and the tongue but not between smokers and nonsmokers. The saliva samples from smokers were enriched with the genera Treponema and Selenomonas. The tongue samples from smokers were enriched with the genera Dialister and Atopobium. The genus Cardiobacterium in saliva, and the genus Granulicatella on the tongue, were negatively correlated with BI values. On the other hand, the genera Treponema, Oribacterium, Dialister, Filifactor, Veillonella, and Selenomonas in saliva and Dialister, Bifidobacterium, Megasphaera, Mitsuokella, and Cryptobacterium on the tongue were positively correlated with BI values.
Conclusions: The saliva and tongue microbial profiles of smokers and nonsmokers differed in periodontally healthy adults. The genera associated with periodontitis and oral malodor accounted for high proportions in saliva and on the tongue of smokers without periodontitis and were positively correlated with lifetime exposure to smoking. The tongue might be a reservoir of pathogens associated with oral disease in smokers.
Experiment 1
Reviewed Marked as Reviewed by Fatima on 2023-4-3
Curated date: 2023/03/13
Curator:
Revision editor(s):
Subjects
- Location of subjects
- Japan
- Host species Species from which microbiome was sampled. Contact us to have more species added.
- Homo sapiens
- Group 0 name Corresponds to the control (unexposed) group for case-control studies
- Nonsmokers
- Group 1 name Corresponds to the case (exposed) group for case-control studies
- Smokers
- Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group
- Smokers who have smoked 100 or more cigarettes since they started smoking.
- Group 0 sample size Number of subjects in the control (unexposed) group
- 32
- Group 1 sample size Number of subjects in the case (exposed) group
- 18
- Antibiotics exclusion Number of days without antibiotics usage (if applicable) and other antibiotics-related criteria used to exclude participants (if any)
- The both groups did not take any antibiotics 3 months prior to the study.
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
- Roche454
Statistical Analysis
- Data transformation Data transformation applied to microbial abundance measurements prior to differential abundance testing (if any).
- relative abundances
- Statistical test
- Mann-Whitney (Wilcoxon)
- 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
- unchanged
- Richness Number of species
- unchanged
Signature 1
Source: figure 3a
Description: Bacteria genera in saliva that differed significantly between smokers and nonsmokers.
Abundance in Group 1: increased abundance
in
NCBI | Quality Control | Links |
---|
Selenomonas | | |
Treponema | | |
Revision editor(s): Chioma,
WikiWorks
Signature 2
Source: figure 3a
Description: Bacteria genera in saliva that differed significantly between smokers and nonsmokers.
Abundance in Group 1: decreased abundance
in
NCBI | Quality Control | Links |
---|
Capnocytophaga | | |
Cardiobacterium | | |
Revision editor(s): Chioma,
WikiWorks
Experiment 2
Reviewed Marked as Reviewed by Fatima on 2023-4-3
Curated date: 2023/03/23
Curator:
Revision editor(s):
Differences from previous experiment shown
Subjects
- Body site Anatomical site where microbial samples were extracted from according to the Uber Anatomy Ontology
- Tongue Glossus,Tongue,tongue
Lab analysis
- Sequencing platform Manufacturer and experimental platform used for quantifying microbial abundance
- Illumina
Statistical Analysis
Alpha Diversity
- Shannon Estimator of species richness and species evenness: more weight on species richness
- unchanged
- Richness Number of species
- unchanged
Signature 1
Source: figure 3b
Description: Bacteria genera in tongue that differed significantly between smokers and nonsmokers
Abundance in Group 1: increased abundance
in
NCBI | Quality Control | Links |
---|
Atopobium | | |
Dialister | | |
Revision editor(s): Chioma,
WikiWorks
Signature 2
Source: figure 3b
Description: Bacteria genera in tongue that differed significantly between smokers and nonsmokers
Abundance in Group 1: decreased abundance
in
NCBI | Quality Control | Links |
---|
Catonella | | |
Gemella | | |
Granulicatella | | |
Haemophilus | | |
Peptostreptococcaceae | | |
Peptostreptococcus | | |
Revision editor(s): Chioma,
WikiWorks