Investigation of the Oral Microbiome in Pregnancy - do Differences in Oral Bacterial Profiles and Nitrate Metabolism Contribute to Blood Pressure Regulation in Pregnant Women?
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 55
- 试验地点
- 1
- 主要终点
- Difference between groups in nitrate/nitrite concentrations before and after dietary nitrate dose
研究概览
简要总结
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).
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Factorial
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 16 Years 至 45 Years（Child, Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •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
排除标准
- •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)
结局指标
主要结局
Difference between groups in nitrate/nitrite concentrations before and after dietary nitrate dose
时间窗: Baseline to 2.5 hour post-nitrate dose
Measurement of plasma and salivary nitrate and nitrite concentrations, using high-performance liquid chromatography (HPLC)
Oral bacterial nitrate reductase activity
时间窗: Baseline
Assessment of oral nitrate reductase activity, measured using enzyme assay
Quantity of oral nitrate reducing bacterial species
时间窗: Baseline
Assessment of oral bacterial profile using next-generation sequencing (bacterial 16S rRNA sequencing)
次要结局
- Difference between groups in blood pressure response to dietary nitrate dose(Baseline to 2.5 hour post-nitrate dose)
研究者
Dr Jenny Myers
Principal Investigator
University of Manchester