The Effect of Dietary Nitrate on the Oral Microbiome

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

Detailed Description
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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.

Official Title
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The Effect of Dietary Nitrate on the Oral Microbiota, Markers of Nitric Oxide Bioavailability and Cardiovascular Health in in Young and Older Adults

Conditions
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Cardiovascular Health, Identify Oral Bacteria Responsible for Nitrate Reduction

Intervention / Treatment
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* Dietary Supplement: Nitrate-rich beetroot juice
* Dietary Supplement: Nitrate-depleted beetroot juice
* Other: Mouthwash


Participation Criteria
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Eligibility Criteria
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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.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Nitrate-rich beetroot juice<br>2 x 70mL concentrated juice per day for 14 days | Dietary Supplement: Nitrate-rich beetroot juice<br>* concentrated beetroot juice<br>|
| Placebo Comparator: Nitrate-depleted beetroot juice<br>2 x 70mL concentrated juice per day for 14 days | Dietary Supplement: Nitrate-depleted beetroot juice<br>* concentrated beetroot juice<br>|
| Other: Antibacterial mouthwash<br>2 x 10mL antibacterial mouthwash per day for 14 days | Other: Mouthwash<br>* 2 x 10 mL antibacterial mouthwash per day for 14 days<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quantity of nitrate -reducing bacteria | Change in total quantity of nitrate-reducing bacteria as measured by sequencing bacterial 16S rRNA genes | 14 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Nitric oxide bioavailability - plasma nitrite | Change in nitrite concentration of plasma as measured by ozone-based chemiluminescence | 14 days | 
| Nitric oxide bioavailability - salivary nitrite | Change in nitrite concentration of saliva as measured by ozone-based chemiluminescence | 14 days | 
| Nitric oxide bioavailability - plasma nitrate | Change in nitrate concentration of plasma as measured by ozone-based chemiluminescence | 14 days | 
| Nitric oxide bioavailability - salivary nitrate | Change in nitrate concentration of saliva as measured by ozone-based chemiluminescence | 14 days | 
| Blood pressure | Change in systolic and diastolic BP | 14 days | 
| Flow mediated dilation | Change in flow mediated dilation | 14 days |