Rothia is the second most abundant bacterial genus in your mouth — about 1 in 9 of your oral bacteria. It's one of the most active at converting dietary nitrate into nitric oxide, the molecule your blood vessels use to stay relaxed. Higher Rothia tracks with healthier blood pressure markers in published research.
Eat more leafy greens and beets. In a controlled trial, 10 days of dietary nitrate raised Rothia by 127% with corresponding plasma nitrite increases.
Daily chlorhexidine and alcohol-based mouthwashes. They kill Rothia and other nitrate-reducing bacteria non-selectively, with measurable effects on blood pressure within one day.
What you can do
Because Rothia is health-associated and enzymatically central to the nitric oxide pathway, the literature supports interventions that increase its abundance and activity.
Dietary nitrate (the strongest evidence)
- Leafy greens (spinach, arugula, lettuce), beets, and beetroot juice are naturally rich in nitrate.
- A controlled trial of older adults gave 12 mmol of nitrate per day (roughly equivalent to 500 g of leafy greens daily) for 10 days. Rothia rose substantially. Plasma nitrite rose. Blood pressure fell.
- In a lab study, nitrate raised Rothia by nearly 3x within five hours.
Periodontal treatment when indicated
Scaling and root planing combined with appropriate antibiotics has been shown to raise Rothia's relative proportion at about three months as the community shifts back toward a health-associated profile.
Timeframe
Dietary nitrate effects can be measurable within hours in lab settings and within days in living people. Sustained effects need sustained intake — Rothia drops back when the dietary nitrate stops.
What does NOT work, or backfires
Chlorhexidine mouthwash for daily use. Non-selectively kills Rothia and other nitrate reducers. Has been shown to drop nitrite production by 90% and raise blood pressure measurably within one day. The single most important "do not" for preserving nitrate-reducing capacity. Short clinical courses under dental supervision are appropriate; daily use is not.
Alcohol-based daily mouthwashes. Similar non-selective effects on the oral community.
Heavy daily antiseptic mouthwash use generally. When the goal is maintaining Rothia and the broader nitrate-reducing community, daily antiseptic use works against you.
Limited evidence so far
For probiotics specifically containing Rothia, or for direct effects of exercise, sleep, or stress on Rothia abundance.
Sources: Vanhatalo 2018 · Kapil 2013
Species pages
Deeper writeups for individual species in this genus.
Synthesized from 9 peer-reviewed sources · Last updated April 2026
This information is for wellness purposes only and is not a medical assessment. Always consult a medical professional about any health concerns.