How Your Mouth Affects Your Heart

The nitric oxide pathway

Nitric oxide is one of the most important molecules in your body. It tells your blood vessels to relax. When they relax, blood flows more easily, blood pressure stays lower, and your heart does not have to work as hard.

Your body makes nitric oxide in two ways. One involves an enzyme called eNOS that works inside your blood vessel walls. The other involves bacteria in your mouth. That second pathway accounts for roughly half of your total nitric oxide production.

Here is how it works:

1. You eat vegetables rich in nitrate — spinach, beets, arugula, celery.
2. Your body absorbs the nitrate and concentrates it in your saliva at levels 10 to 20 times higher than in your blood.
3. Specific bacteria on your tongue — mainly Neisseria and Rothia species — convert that nitrate into nitrite.
4. When you swallow, stomach acid converts the nitrite into nitric oxide, which enters your bloodstream and relaxes your arteries.

Without the right bacteria, step three never happens. The nitrate from your salad just passes through without doing what it should.

Why Neisseria matters

When Cnvrg measures your oral microbiome, one of the key things we look at is the abundance of nitrate-reducing bacteria — especially Neisseria species. These are not harmful. They are some of the most important bacteria in your mouth.

When Neisseria is depleted, the downstream effects show up in places you would not expect:

Blood pressure goes up. Dr. Vikas Kapil and his team at Queen Mary University of London showed that using antiseptic mouthwash for just seven days reduced oral nitrite production by 90%, dropped plasma nitrite by 25%, and raised systolic blood pressure by 2 to 3 points. That might sound small, but even a 2-point rise in systolic blood pressure is associated with a 10% increase in stroke mortality.

LDL does more damage. Nitric oxide prevents LDL cholesterol from penetrating and oxidizing inside artery walls. When nitric oxide drops, arteries become stiffer and more vulnerable to cholesterol buildup. A statin manages how much LDL is in your blood. Nitric oxide determines how much damage that LDL can do.

Resting heart rate rises. When blood vessels are stiff, the heart has to push harder with every beat. That extra effort shows up as a higher resting heart rate on your wearable. Most people think resting heart rate is purely a fitness metric. It is. But it is also downstream of your oral microbiome.

Inflammation increases. Nitric oxide directly suppresses the inflammatory cascade driven by NF-kB. When nitric oxide drops, CRP and other inflammatory markers tend to rise. CRP is one of the nine markers in the PhenoAge blood age formula. So the health of your mouth can literally affect how old your blood looks.

What Cnvrg sees that nobody else does

A cardiologist looking at your blood panel sees elevated LDL and prescribes a statin. A dentist looking at your gums sees inflammation and recommends better flossing. Neither one sees the nitric oxide connection between the two.

Cnvrg measures your oral microbiome, your blood biomarkers, and your wearable data simultaneously. When your Neisseria is depleted and your LDL is elevated and your resting heart rate is climbing, Cnvrg connects those dots. That is the connection line you see on your marker pages.

This is not speculative. The oral nitric oxide pathway is one of the best-studied connections between the mouth and the cardiovascular system, supported by randomized controlled trials, large cohort studies, and decades of mechanistic research.

What you can do about it

The good news is that this pathway is one of the most modifiable things in your health profile.

Eat more nitrate-rich vegetables. Arugula, spinach, beets, celery, and radishes are all high in dietary nitrate. These are the raw materials your oral bacteria need to make nitric oxide.

Try a beetroot juice protocol. Ten days of concentrated beetroot juice has been shown to measurably increase plasma nitrite and support blood pressure. Some people see changes within a few days.

Exercise consistently. Zone 2 cardio — the kind where you can still hold a conversation — directly improves both cardiovascular fitness and the efficiency of the nitric oxide pathway. About 150 minutes per week is the threshold where benefits become measurable.

Rebuild your nitrate-reducing bacteria. If your Neisseria levels are depleted, stopping antiseptic mouthwash and increasing dietary nitrate are the two most evidence-based steps. See our article on mouthwash and your microbiome for the full picture.

Your mouth and your heart are not separate systems. They are connected through a pathway that you can measure, track, and improve.

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Sources

1. Kapil V, et al. Physiological role for nitrate-reducing oral bacteria in blood pressure control. Free Radical Biology and Medicine. 2013;55:93-100. PMID: 23201780
2. Joshipura K, et al. Over-the-counter mouthwash use and risk of pre-diabetes/diabetes. Nitric Oxide. 2017;71:14-20.
3. Blot S, et al. Antiseptic mouthwash, the nitrate-nitrite-nitric oxide pathway, and hospital mortality. Intensive Care Medicine. 2020.
4. Vanhatalo A, et al. Nitrate-responsive oral microbiome modulates nitric oxide homeostasis and blood pressure in humans. Free Radical Biology and Medicine. 2018;124:160-169.
5. Stahl M, et al. Oral nitrate-reducing capacity correlates with VO2 at ventilatory threshold. Am J Physiol Heart Circ Physiol. 2025.