Impact of HbA1c control and type 2 diabetes mellitus exposure on the oral microbiome profile in the elderly population

Abstract

Objective To investigate the associations of the oral microbiome status with diabetes characteristics in elderly patients with type 2 diabetes mellitus.Methods A questionnaire was used to assess age, sex, smoking status, drinking status, flossing frequency, T2DM duration and complications, and a blood test was used to determine the glycated haemoglobin (HbA1c) level. Sequencing of the V3-V4 region of the 16S rRNA gene from saliva samples was used to analyze the oral microbiome.Results Differential analysis revealed that Streptococcus and Weissella were significantly enriched in the late-stage group, and Capnocytophaga was significantly enriched in the early-stage group. Correlation analysis revealed that diabetes duration was positively correlated with the abundance of Streptococcus (r= 0.369, p= 0.007) and negatively correlated with the abundance of Cardiobacterium (r= -0.337, p= 0.014), and the level of HbA1c was not significantly correlated with the oral microbiome. Network analysis suggested that the poor control group had a more complex microbial network than the control group, a pattern that was similar for diabetes duration. In addition, Streptococcus has a low correlation with other microorganisms.Conclusion In elderly individuals, Streptococcus emerges as a potential biomarker linked to diabetes, exhibiting elevated abundance in diabetic patients influenced by disease exposure and limited bacterial interactions.

Keywords

• Elderly individuals
• type 2 diabetes mellitus
• oral microbiome
• glycated haemoglobin
• diabetes duration