The role of dietary nitrate and chlorohexidine mouthwash on the oral microbiome and salivary pellicle proteins of individuals with dental erosion (DE)

Project Details


DE, which involves the loss of the hard tooth substances due to acid exposure from exogenous (food and drink) (Buzalaf et al, 2012) and endogenous (stomach acid) (Moazzez and Bartlett, 2014) sources, is becoming a global pandemic leading to consequences from sensitivity to cold air/water to pain and irreversible nerve damage in the tooth resulting in need for root canal treatment or other expensive restorative dental treatment or tooth loss (Bartlett and O'Toole, 2020). Immediately after teeth brushing, a thin film called salivary pellicle (SP), consisting mainly of salivary proteins, but also some microbes, selectively adsorbs to the oral surfaces such as enamel and tongue and protects against DE (Bartlett and O'Toole, 2019).

Greater abundance of oral nitrate-reducing bacteria (NRB) has been positively associated with oral and general health (Rosier et al,2022). Nitrate (NO3-) from the circulation is secreted into the oral cavity wherein oral NRB reduce salivary NO3- to nitrite (NO2-) (Duncan et al. 1995). In addition, NRB increase salivary pH (Burleigh et al., 2020), which further facilitates NO3- reduction to NO2- (Cocksedge et al. 2023). This NO2- is then swallowed and can be systemically reduced nitric oxide (NO) (Lundberg et al, 2008), an important vasodilator that improves cardiovascular health. Accordingly, NRB has been associated with lower blood pressure (Bescos et al, 2020). Nitrate supplementation has been shown to positively modulate the activity of nitrate reducing bacteria (NRB), enhancing the conversion of nitrate into beneficial nitric oxide (Burleigh et al., 2019). Conversely, Chlorohexidine (CHX) mouthwash, by eradicating NRB, abolishes the oral conversion of NO3- to NO2- and the blood pressure lowering effect of NO3- supplementation (Petersson et al.,2009).

Layperson's description

Dental erosion (DE), the wearing away of tooth substances due to acid exposure from both external sources like food and drink and internal sources like stomach acid, is a global issue. DE can lead to tooth sensitivity, pain, nerve damage, and the need for expensive dental treatments or even tooth loss.

Shortly after tooth brushing, a protective layer called the "salivary pellicle" (SP) forms on teeth, composed mainly of salivary proteins and some microbes, guarding against DE.

Oral health is connected to overall health, and nitrate-reducing bacteria (NRB) in the mouth are associated with improved oral and cardiovascular health. These NRB convert nitrate (NO3-) in the bloodstream to nitrite (NO2-) in the mouth. Nitrite can be further converted to nitric oxide (NO), a vasodilator that benefits cardiovascular health, ultimately lowering blood pressure.

Supplementing with nitrate enhances NRB activity, increasing the conversion of nitrate to nitric oxide. Conversely, using Chlorohexidine (CHX) mouthwash eradicates NRB, hindering nitrate conversion and the potential blood pressure-lowering effect.

In summary, dental erosion is a widespread concern, and the presence of specific mouth bacteria can impact both oral and overall health, highlighting the intricate relationship between oral hygiene and systemic well-being.

Key findings

Not yet executed.
Short titleNitrate/chlorohexidine
Effective start/end date31/10/2330/06/24