Subgingival Microbiota of Mexicans with Type 2 Diabetes with Different Periodontal and Metabolic Conditions

Background: Type-2-Diabetes (T2D) and Periodontitis are major inflammatory diseases. However, not much is known about the specific subgingival microbiota in Mexicans with diabetes and metabolic dysbiosis. The aim of this study was to describe the subgingival microbiota of Mexicans with T2D and the different periodontal and metabolic conditions, through “Checkerboard” DNA–DNA hybridization. Methods: Subjects were divided into two groups—periodontal-health (PH) (PH_non-T2D; n = 59, PH_T2D; n = 14) and generalized-periodontitis (GP) (GP_non-T2D; n = 67, GP_T2D; n = 38). Obesity (BMI ≥ 30 kg/m 2 ) and serum levels of glycated-hemoglobin (HbA1c), total-lipids, triglycerides, total-cholesterol, high-density-lipids, and low-density-lipids were measured for the T2D individuals. Subgingival microbial identification was processed for 40 species through DNA-probes. Results: Subjects with T2D harbored significantly higher mean total levels (PH: p < 0.001, and GP_NS), a lower proportion of “red” complex (GP: p < 0.01), a higher proportion of “yellow” (GP; p < 0.001), and “orange” (GP; p < 0.01) complex than the non-T2D. GP_T2D individuals exhibited a greater proportion of putative-species— Campylobacter gracilis and S. constellatus ( p < 0.001), and Parvimonas micra and Prevotella nigrescens ( p < 0.01), than GP_non-T2D. T2D individuals with HbA1c > 8% had presented significantly higher mean pocket-depth and higher levels of G. morbillorum ( p < 0.05) and those with obesity or dyslipidemia harbored higher levels, prevalence, or proportion of Streptococcus sp., Actinomyces sp., and Capnocytophaga sp. Conclusions: T2D individuals harbored a particular microbial profile different to non-T2D microbiota. Metabolic control was related to dysbiosis of microbiota—HbA1c>8% related to periodontitis and obesity or dyslipidemia with the predominance of saccharolytic bacteria, irrespective of their periodontal condition.