Dietary Nitrate and the Oral Microbiome in Children With Primary Hypertension

Children and adolescents with primary hypertension (high blood pressure without an underlying secondary cause) are at increased risk of cardiovascular disease in adulthood. Recent research suggests that not only the heart and blood vessels, but also the bacteria living in the mouth may play a role in blood pressure regulation. Certain oral bacteria can convert nitrate from food into nitrite and then into nitric oxide, a substance that helps blood vessels relax. If this nitrate-nitrite-nitric oxide pathway is impaired, blood pressure may rise.

This study aims to investigate the relationship between oral microbiota, salivary nitric oxide reductase activity and blood pressure in children and adolescents with primary hypertension compared with healthy peers. We will recruit participants aged 10-18 years who have a diagnosis of primary hypertension and an age- and sex-matched control group without hypertension.

All participants will undergo a non-invasive oral and dental examination and standardized blood pressure measurements. Saliva samples will be collected to measure pH, flow rate, nitrate and nitrite levels, total protein, lysozyme activity and to analyze the composition of oral bacteria using modern DNA-based techniques. Participants and/or their parents will also complete brief questionnaires about diet and general health.

No medication or dietary supplement will be given as part of the study, and no additional blood samples will be taken beyond routine clinical care. The main risk is minimal discomfort related to oral examination and saliva collection. There is no guaranteed direct benefit for participants; however, the results may help us better understand how oral bacteria and salivary nitric oxide pathways are linked to high blood pressure in young people. This knowledge may support the development of new non-invasive strategies for early detection and prevention of hypertension in the future.