Sex Differences in Oral Bacteria

Inclusion Criteria: * Healthy subjects aged 18-45 who have volunteered themselves and are willing to sign the consent form Exclusion Criteria: 1. Healthy subjects unwilling to consent 2. History of hypertension, diabetes or hypertensive on BP measurement 3. Pregnant, or any possibility that a subject may be pregnant unless in the latter case a pregnancy test is performed with a negative result 4. History of any serious illnesses, including recent infections or trauma 5. Subjects taking systemic medication (other than the oral contraceptive pill) 6. Subjects with self-reported use of mouthwash or tongue scrapes 7. Subjects with recent or current antibiotic use (within 3 months) 8. Subjects with a history, or recent treatment of (within last 3 months) of any oral condition (excluding caries), including gingivitis, periodontitis and halitosis