Role of the Oral Microbiome in Blood Pressure Regulation in Pregnancy

NCT ID: NCT03930693

Last Updated: 2024-05-16

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 55 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2019-06-06
• Study Completion Date: 2022-03-31

Brief Summary

High blood pressure in pregnancy is associated with poor outcomes for both mum and baby, increasing the risk of pregnancy complications including pre-eclampsia, fetal growth restriction and preterm birth. The development of new blood pressure lowering interventions suitable for use in pregnancy is a key research priority.

Inorganic nitrate is a compound found in certain types of food, particularly green leafy vegetables and beetroot. Nitrate provides an important source of nitric oxide (NO), a molecule involved in keeping blood vessels healthy and regulating blood pressure. Supplementation with nitrate in the diet, using interventions such as beetroot juice, has been shown to reduce blood pressure and improve blood vessel function.

In order for dietary nitrate to have these beneficial effects, it needs to be converted in the body to nitrite, via bacteria that live in the mouth (oral bacteria). Differences in oral bacteria, and how they metabolise nitrate, are thought to influence blood pressure regulation and potentially response to dietary nitrate supplementation.

This study aims to understand (1) whether pregnant women with high blood pressure have a different composition of oral bacteria compared to healthy pregnant women and women who are not pregnant, and (2) how differences in oral bacteria affect blood pressure responses to a dose of dietary nitrate (in the form of beetroot juice).

Conditions

Gestational Hypertension

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: FACTORIAL
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Normotensive pregnant women

Normotensive pregnant women

Group Type: EXPERIMENTAL

Beetroot juice

Intervention Type: DIETARY_SUPPLEMENT

Beetroot juice shot (70mL containing 400mg inorganic nitrate)

Hypertensive pregnant women

Hypertensive pregnant women

Group Type: EXPERIMENTAL

Beetroot juice

Intervention Type: DIETARY_SUPPLEMENT

Beetroot juice shot (70mL containing 400mg inorganic nitrate)

Normotensive non-pregnant women

Normotensive non-pregnant women

Group Type: EXPERIMENTAL

Beetroot juice

Intervention Type: DIETARY_SUPPLEMENT

Beetroot juice shot (70mL containing 400mg inorganic nitrate)

Hypertensive non-pregnant women

Hypertensive non-pregnant women

Group Type: EXPERIMENTAL

Beetroot juice

Intervention Type: DIETARY_SUPPLEMENT

Beetroot juice shot (70mL containing 400mg inorganic nitrate)

Interventions

Beetroot juice

Beetroot juice shot (70mL containing 400mg inorganic nitrate)

Intervention Type: DIETARY_SUPPLEMENT

Eligibility Criteria

Inclusion Criteria

• Normotensive or hypertensive women (hypertension as systolic blood pressure >140 mmHg and/or diastolic blood pressure >90 mmHg OR on anti-hypertensive medication)
• For pregnant women, between 20-28 weeks gestation

Exclusion Criteria

• Multi-fetal pregnancy (for pregnant women)
• Age under 16, or over 45 years of age
• Lacking ability to consent
• Pre-existing diabetes (Type 1/Type 2)
• Previous history of pre-term FGR (delivery before 32 weeks with FGR)
• Current tobacco smoker
• Body Mass Index greater than or equal to 40 or less than or equal to 18
• Use of any of the following drugs in the last 6 months: systemic antibiotics, antifungals, antivirals or antiparasitics (intravenous, intramuscular, or oral)
• Large doses of commercial probiotics (greater than or equal to 108 cfu or organisms per day) including tablets, capsules, lozenges, chewing gum or powders (ordinary dietary components such as yoghurts do not apply)
• Evidence of oral disease, assessed on screening proforma (current conditions of: oral candidiasis (thrush); Dental caries (tooth decay); Halitosis; Oral ulcerations/mouth ulcers; Wisdom tooth pain; Chronic dry mouth)
• Allergy to beetroot juice or lemon juice (both contained within the juice shot)

• Minimum Eligible Age: 16 Years
• Maximum Eligible Age: 45 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: Yes

Sponsors

University of Manchester

OTHER

Sponsor Role: lead

Responsible Party

Dr Jenny Myers

Principal Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Jenny Myers, BM, PhD

Role: PRINCIPAL_INVESTIGATOR

Manchester University NHS Foundation Trust

Locations

Maternal and Fetal Health Research Centre, St Mary's Hospital

Manchester, , United Kingdom

Countries

United Kingdom

References

Willmott T, Ormesher L, McBain AJ, Humphreys GJ, Myers JE, Singh G, Lundberg JO, Weitzberg E, Nihlen C, Cottrell EC. Altered Oral Nitrate Reduction and Bacterial Profiles in Hypertensive Women Predict Blood Pressure Lowering Following Acute Dietary Nitrate Supplementation. Hypertension. 2023 Nov;80(11):2397-2406. doi: 10.1161/HYPERTENSIONAHA.123.21263. Epub 2023 Sep 13.

Reference Type: DERIVED

PMID: 37702047 (View on PubMed)

Other Identifiers

246813

Identifier Type: -

Identifier Source: org_study_id