ABSTRACT
BACKGROUND AND OBJECTIVE: The oral microbiome may help to maintain systemic health, including how it affects blood glucose levels; however, direct evidence linking the oral microbiome with diabetes is lacking. MATERIAL AND METHODS: We compared the oral microbiome profiles of 98 participants with incident diabetes, 99 obese non-diabetics and 97 normal weight non-diabetics, via deep sequencing of the 16S rRNA gene. RESULTS: We found that the phylum Actinobacteria was present significantly less abundant among patients with diabetes than among the controls (p = 3.9 × 10-3 ); the odds ratio (OR) and 95% confidence interval (CI) was 0.27 (0.11-0.66) for those individuals who had relative abundance higher than the median value. Within this phylum, five families and seven genera were observed, and most of them were less abundant among patients with diabetes. Notably, genera Actinomyces and Atopobium were associated with 66% and 72% decreased risk of diabetes with p-values of 8.9 × 10-3 and 7.4 × 10-3 , respectively. Stratified analyses by race showed that most taxa in this phylum were associated with diabetes in both black and white participants. This phylum was also less abundant among non-diabetic obese subjects compared to normal weight individuals, particularly genera Mobiluncus, Corynebacterium and Bifidobacterium, which showed p < 0.05. CONCLUSION: Our study revealed that multiple bacteria taxa in the phylum Actinobacteria are associated with the risk of type 2 diabetes. Some are also associated with the prevalence of obesity, suggesting that the oral microbiome may play an important role in diabetes etiology.
Subject(s)
Diabetes Mellitus, Type 2/etiology , Microbiota , Mouth/microbiology , Actinobacteria/genetics , Actinomyces/genetics , Adult , Aged , Bifidobacterium/genetics , Case-Control Studies , Corynebacterium/genetics , Diabetes Mellitus, Type 2/microbiology , Female , High-Throughput Nucleotide Sequencing/methods , Humans , Male , Middle Aged , Obesity/microbiology , RNA, Ribosomal, 16S/genetics , Risk FactorsABSTRACT
BACKGROUND: While studies have shown that poor oral health status may increase the risk of cancer, evidence of a specific association with the risk of colorectal cancer (CRC) is inconclusive. We evaluated the association between oral health and CRC risk using data from three large cohorts: the Shanghai Men's Health Study (SMHS), the Shanghai Women's Health Study (SWHS), and the Southern Community Cohort Study (SCCS), and carried out a meta-analysis of results from other relevant published studies. PATIENTS AND METHODS: This study applied a nested case-control study design and included 825 cases/3298 controls from the SMHS/SWHS and 238 cases/2258 controls from the SCCS. The association between oral health status (i.e. tooth loss/tooth decay) and CRC risk was assessed using conditional logistic regression models. A meta-analysis was carried out based on results from the present study and three published studies. RESULTS: We found that tooth loss was not associated with increased risk of CRC. ORs and respective 95% CIs associated with loss of 1-5, 6-10, and >10 teeth compared with those with full teeth are 0.87 (0.69-1.10), 0.93 (0.70-1.24), and 0.85 (0.66-1.11) among SMHS/SWHS participants; and 1.13 (0.72-1.79), 0.87 (0.52-1.43), and 1.00 (0.63-1.58) for those with loss of 1-4, 5-10, and >10 teeth among SCCS participants. Data regarding tooth decay were available in the SCCS, but were not associated with CRC risk. Meta-analysis confirmed the null association between tooth loss/periodontal disease and CRC risk (OR 1.05, 95% CI 0.86-1.29). CONCLUSION: In this analysis of three cohorts and a meta-analysis, we found no evidence supporting an association between oral health and CRC risk.
