People with more oral bacteria that convert nitrates to nitrites tend to have lower blood sugar levels.

People with more oral bacteria that convert nitrates to nitrites tend to have better insulin sensitivity, meaning their bodies handle sugar better.

The amount of oral bacteria that convert nitrates to nitrites doesn't seem to be related to whether people have prediabetes or high blood pressure.

Eating foods with inorganic nitrate might change the bacteria in the mouths of people with type 2 diabetes—making some helpful bacteria grow more and others shrink—which could help their bodies make more nitric oxide, a molecule that helps blood flow.

Even after accounting for many other factors that could affect insulin sensitivity, the link between oral bacteria that convert nitrates to nitrites and better insulin sensitivity still holds true.

The amount of oral bacteria that convert nitrates to nitrites varies a lot between people, from less than 0.1% to over 85% of all oral bacteria.