Browse evidence-based analysis of health-related claims and assertions
In rats, the bacteria in the mouth are different from those on the skin and in the gut, with Actinobacteria and Proteobacteria being the most common types in the mouth.
Descriptive
In rats, the types and amounts of bacteria on the skin differ between males and females, but this difference isn't seen in the mouth or gut bacteria.
In rats prone to high blood pressure, the amount of Cyanobacteria bacteria on the skin is linked to blood pressure levels, but this connection is different for male and female rats.
Correlational
In rats that are prone to high blood pressure, having more of a certain type of bacteria (Actinobacteria) in the mouth is linked to lower blood pressure.
In pregnant women, the amount of Veillonella dispar bacteria in the mouth wasn't linked to systolic blood pressure, but showed a similar pattern to diastolic blood pressure that wasn't quite statistically significant.
In pregnant women, the amount of Prevotella bacteria in the mouth wasn't linked to blood pressure levels.
The types and amounts of bacteria in the mouths of pregnant women who later got preeclampsia were more varied between individuals compared to women who stayed healthy.
Pregnant women who later got preeclampsia ate about the same amount of nitrate-rich vegetables (like spinach and beets) as women who stayed healthy during pregnancy.
Pregnant women who later got preeclampsia had more of several specific bacteria types (Methanosaeta, Desulfomicrobium, Enterococcus, Mycobacterium, Thiobacillus, and Ochrobactrum) in their mouths compared to women who stayed healthy.
In pregnant women, higher levels of Veillonella bacteria in the mouth were linked to higher levels of Prevotella bacteria.
The amount of a specific gene involved in nitrate reduction (narH) was similar in the mouths of pregnant women who later got preeclampsia and those who stayed healthy.
In pregnant women, higher levels of Veillonella parvula bacteria in the mouth were linked to lower diastolic blood pressure, and showed a similar but less strong pattern for systolic blood pressure.
In pregnant women, having more Veillonella bacteria in the mouth was linked to lower blood pressure readings.
Pregnant women who later got preeclampsia had less of a specific bacteria called Veillonella parvula in their mouths compared to women who stayed healthy during pregnancy.
When mouth bacteria are disrupted, blood pressure goes up regardless of how it's measured - whether at the doctor's office, at home, or with a 24-hour monitor.
Quantitative
Using mouthwash that kills mouth bacteria might be bad for heart health because it raises blood pressure by disrupting the body's natural nitrite balance.
The process where nitrate moves from blood to saliva and gets converted to nitrite by mouth bacteria is important for keeping nitrite levels stable in the blood.
Bacteria in the mouth help regulate blood pressure by converting nitrate to nitrite, which is part of the body's natural blood pressure control system.
Mechanistic
Using mouthwash that kills mouth bacteria raises blood pressure during both day and night, with bigger increases during the day.
There's a clear connection between how much nitrite is in the blood and blood pressure changes when mouth bacteria are disrupted, with a strong statistical relationship.
Using mouthwash that kills mouth bacteria leads to higher levels of nitrate in both saliva and blood.
When people start using mouthwash that kills mouth bacteria, their blood pressure can go up within just one day.
Bacteria in the mouth help keep nitrite levels in the blood stable, which is shown by the fact that people with higher nitrite in their saliva also tend to have higher nitrite in their blood.
When bacteria that help convert nitrate to nitrite in the mouth are reduced, blood pressure tends to go up by a small amount (2-3.5 mmHg for systolic and 2-2.2 mmHg for diastolic).