The Effect of Dietary Nitrate on the Oral Microbiome (Microbio)

• ClinicalTrials.gov Identifier: NCT03467061
• Recruitment Status: Completed
• First Posted: March 15, 2018
• Last Update Posted: May 27, 2021
• Sponsor: University of Exeter
• Information provided by (Responsible Party): University of Exeter

Study Description

Brief Summary:

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

Condition or disease	Intervention/treatment	Phase
Cardiovascular Health; Identify Oral Bacteria Responsible for Nitrate Reduction	Dietary Supplement: Nitrate-rich beetroot juice; Dietary Supplement: Nitrate-depleted beetroot juice; Other: Mouthwash	Not Applicable

Detailed Description:

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.

Study Design

• Study Type: Interventional (Clinical Trial)
• Actual Enrollment: 101 participants
• Allocation: Randomized
• Intervention Model: Crossover Assignment
• Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
• Primary Purpose: Basic Science
• Official Title: The Effect of Dietary Nitrate on the Oral Microbiota, Markers of Nitric Oxide Bioavailability and Cardiovascular Health in in Young and Older Adults
• Actual Study Start Date: January 10, 2018
• Actual Primary Completion Date: May 6, 2021
• Actual Study Completion Date: May 6, 2021

Arms and Interventions

Arm	Intervention/treatment
Active Comparator: Nitrate-rich beetroot juice; 2 x 70mL concentrated juice per day for 14 days	Dietary Supplement: Nitrate-rich beetroot juice; concentrated beetroot juice
Placebo Comparator: Nitrate-depleted beetroot juice; 2 x 70mL concentrated juice per day for 14 days	Dietary Supplement: Nitrate-depleted beetroot juice; concentrated beetroot juice
Antibacterial mouthwash; 2 x 10mL antibacterial mouthwash per day for 14 days	Other: Mouthwash; 2 x 10 mL antibacterial mouthwash per day for 14 days

Outcome Measures

Primary Outcome Measures :

1. Quantity of nitrate -reducing bacteria [ Time Frame: 14 days ]
   Change in total quantity of nitrate-reducing bacteria as measured by sequencing bacterial 16S rRNA genes

Secondary Outcome Measures :

1. Nitric oxide bioavailability - plasma nitrite [ Time Frame: 14 days ]
   Change in nitrite concentration of plasma as measured by ozone-based chemiluminescence
2. Nitric oxide bioavailability - salivary nitrite [ Time Frame: 14 days ]
   Change in nitrite concentration of saliva as measured by ozone-based chemiluminescence
3. Nitric oxide bioavailability - plasma nitrate [ Time Frame: 14 days ]
   Change in nitrate concentration of plasma as measured by ozone-based chemiluminescence
4. Nitric oxide bioavailability - salivary nitrate [ Time Frame: 14 days ]
   Change in nitrate concentration of saliva as measured by ozone-based chemiluminescence
5. Blood pressure [ Time Frame: 14 days ]
   Change in systolic and diastolic BP
6. Flow mediated dilation [ Time Frame: 14 days ]
   Change in flow mediated dilation

Eligibility Criteria

• Ages Eligible for Study: 18 Years to 80 Years (Adult, Older Adult)
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes

Criteria

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.

Contacts and Locations

Locations

United Kingdom

Diabetes & Vascular Medicine Research Centre, Clinical Research Facility

Exeter, Devon, United Kingdom

Sponsors and Collaborators

University of Exeter

Investigators

• Principal Investigator: Andrew M Jones, PhD; University of Exeter

More Information

• Responsible Party: University of Exeter
• ClinicalTrials.gov Identifier: NCT03467061
• Other Study ID Numbers: 1718/14
• First Posted: March 15, 2018
• Last Update Posted: May 27, 2021
• Last Verified: May 2021

• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: No