Inulin and Nitrate's Effects on Vascular Health and Gut Microbiome

Summary

Previous research has revealed that adults with pre-hypertensive and hypertensive blood pressure levels typically exhibit impaired vasodilation, which is a crucial aspect of blood vessel function, due to decreased nitric oxide production. Flow-mediated dilation (FMD) is a widely used technique for assessing vasodilation, which gauges the capacity of blood vessels to widen in response to increased blood flow. Nitrate supplements have been shown to enhance blood vessel function both in the short and long term by elevating nitric oxide (NO) production. Similarly, acetate, a by-product of fibre digestion, has demonstrated anti-inflammatory effects in the gut and may also increase NO production. However, further investigation is needed to determine whether these two supplements work synergistically to improve FMD responses by augmenting NO production in the human body. This study will involve administering inulin plus nitrate supplements to adults aged 45-74 with untreated high blood pressure (120-139/80-89 mmHg and 140/90 mmHg or higher) for a period of 4 weeks, followed by a subsequent 4-week period where only inulin supplements are consumed. The supplements will be provided in the form of powder, to be mixed with water, and will be given in a cross-over and counterbalanced order. Various measurements, including brachial artery function, faecal samples, blood pressure, plasma nitrate and nitrite levels, plasma short-chain fatty acid levels, red blood cell and whole blood S-Nitrosothiols, and salivary nitrate and nitrite levels, will be taken at the baseline and after each supplementation period. Additionally, acute supplementation measurements will be collected on two separate occasions before the start of the longer-term supplement regimen.

Conditions

• Endothelial Dysfunction
• High Blood Pressure
• Gut Microbiota Dysbiosis and Nutrition

Interventions

DIETARY_SUPPLEMENT

Inulin

15 g inulin once daily for 4 weeks.

DIETARY_SUPPLEMENT

Potassium nitrate and inulin

1300 mg potassium nitrate once daily for 4 weeks and 15 g inulin once daily for 4 weeks.

Sponsors & Collaborators

• University of East Anglia

  collaborator OTHER

• University of Exeter

  lead OTHER

Principal Investigators

• Luciana Torquati, PhD · University of Exeter

• Jessica Virgili, MSc · University of Exeter

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

DOUBLE

Model

CROSSOVER

Eligibility

Min Age

45 Years

Max Age

74 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2023-05-09

Primary Completion

2024-07-31

Completion

2024-07-31

Countries

• United Kingdom

Study Locations