This study evaluates whether dietary manipulation of the oral microbiota modulates cardiovascular health through effects on nitric oxide bioavailability.

Nitric oxide is an important molecule for human health because it controls blood flow and blood pressure. With aging, our ability to make nitric oxide gets worse and our blood pressure tends to increase. We can help the body produce more nitric oxide by supplementing the diet with vegetables, such as beetroot juice, which contains high amounts of nitrate. This has been shown to improve blood flow and blood pressure. The bacteria inside our mouths play an important role in helping convert the ingested nitrate to nitric oxide. The reason for this study is to find out whether there are differences in oral bacteria between young and older adults, and how the oral bacterial community and blood flow and blood pressure might change when diet is supplemented with natural, nitrate-rich beetroot juice and when we use antibacterial mouthwash. This study will help us understand how the bacteria inside our mouths might be useful for keeping us healthy.

Inclusion Criteria:

• Healthy young (18-30 yr) and older adults (65-80 yr)
• Male and female
• Willing to undergo the experiments as detailed in the informed consent documentation
• Willing and capable of providing written, informed consent.

Exclusion Criteria:

• Individuals receiving medication for pulmonary, cardiovascular, or metabolic conditions, ulcerative colitis or renal disease
• Having an active oral disease or dentures
• Having resting BP >140/90 mmHg
• Having used antibiotics within 3 months
• Lacking willingness or capacity to give informed consent.