In rats, higher levels of certain mouth bacteria were linked to lower blood pressure, showing how the mouth's bacteria might help control blood pressure.

In rats with different genetic modifications that affect blood pressure, the types and amounts of bacteria in the mouth differ between these strains.

The link between oral bacteria that convert nitrates to nitrites and blood pressure is stronger in people who don't have high blood pressure already.

People with more oral bacteria that convert nitrates to nitrites tend to have lower blood pressure, but only if they don't already have high blood pressure.

The small blood pressure increase from using the special mouthwash was similar in size to what's known to increase the risk of heart disease and stroke.

Researchers wanted to see if differences in mouth bacteria and nitrate-processing ability explain why some people's blood pressure goes down more than others after eating nitrate-rich food.