Diabetes Reversal and the Subgingival Microbiota

Inclusion Criteria: * Men and women undergoing bariatric surgery who are 25-65 years old. * BMI \> 35 kg/m2. * Diabetic subjects: HbA1c\> 6.0% or fasting plasma glucose \>126 mg/dl). * Normoglycemic subjects: HbA1c\<5.75% or fasting plasma glucose \<100 mg/dl). * Dental criteria: Minimum of 4 posterior teeth. * Signed and dated informed consent form. * Willing to comply with all study procedures and be available for the duration of the study. Exclusion Criteria: * Subjects diagnosed with type 1 diabetes, maturity onset diabetes of the young (MODY), or latent autoimmune diabetes in adults (LADA). * Women who are considering pregnancy or are currently breastfeeding. * Individuals with a history of chronic inflammatory or autoimmune diseases or taking medications that affect immune function or affect body weight such as chronic systemic steroids. * Currently smoke more than 10 cigarettes per day. * Periodontal treatment within 3 months of bacterial sampling. * Acute periodontal infection (abscess) within 1 month of bacterial sampling or abscess in teeth or adjacent teeth within 1 month of sampling. * Treatment with antibiotics within one month of sample collection (except as part of the surgical regimen of prophylactic antibiotic immediately prior to surgery). * A treatment regimen of steroids within 1 month of sample collection.