The association of taste genetics and the oral microbiome in autoimmune diseases such as rheumatoid arthritis (RA) has not been reported. We explored a novel oral mucosal innate immune pathway involving the bitter taste G protein-coupled receptor T2R38. This case-control study aimed to evaluate whether T2R38 polymorphisms associate with the buccal microbial composition in RA. Genomic DNA was obtained from buccal swabs of 35 RA patients and 64 non-RA controls. TAS2R38 genotypes were determined by Sanger sequencing. The buccal microbiome was assessed by Illumina MiSeq sequencing of the V4-16S rRNA gene. Bacterial community differences were analyzed with alpha and beta diversity measures. Linear discriminant analysis effect size identified taxa discriminating between RA versus non-RA and across TAS2R38 genotypes. TAS2R38 genotype frequency was similar between RA and non-RA controls (PAV/PAV; PAV/AVI; AVI/AVI: RA 42.9%; 45.7%; 11.4% versus controls 32.8%; 48.4%; 18.8%, chi-square (2, N = 99) = 2.1, p = 0.35). The relative abundance of Porphyromonas, among others, differed between RA and non-RA controls. The relative abundance of several bacterial species also differed across TAS2R38 genotypes. These findings suggest an association between T2R38 polymorphisms and RA buccal microbial composition. However, further research is needed to understand the impact of T2R38 in oral health and RA development.
Experiment 1
Subjects
- Location of subjects
- Canada
- Host species Species from which microbiome was sampled (if applicable)
- Homo sapiens
- Condition The experimental condition / phenotype studied according to the Experimental Factor Ontology
- arthritis arthritic joint disease,arthritides,arthritis,inflammation of skeletal joint,inflammatory disorder of joint,skeletal joint inflammation
- Group 0 name Corresponds to the control (unexposed) group for case-control studies
- Non Rheumatoid Arthritis
- Group 1 name Corresponds to the case (exposed) group for case-control studies
- Rheumatoid Arthritis
- Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group
- Rheumatoid Arthritis patients
- Group 0 sample size Number of subjects in the control (unexposed) group
- 64
- Group 1 sample size Number of subjects in the case (exposed) group
- 35
- Antibiotics exclusion Number of days without antibiotics usage (if applicable) and other antibiotics-related criteria used to exclude participants (if any)
- N/A
Lab analysis
- Sequencing type
- 16S
- Sequencing platform Manufacturer and experimental platform used for quantifying microbial abundance
- Illumina
Statistical Analysis
- Statistical test
- LEfSe
- Significance threshold p-value or FDR threshold used for differential abundance testing (if any)
- .05
- LDA Score above Threshold for the linear discriminant analysis (LDA) score for studies using the popular LEfSe tool
- 2
Alpha Diversity
- Shannon Estimator of species richness and species evenness: more weight on species richness
- unchanged
