Mechanism · 5 min read

The Oral Microbiome & Nitric Oxide: Why Mouthwash Blunts Beetroot's Benefits

Your mouth bacteria are essential for beetroot to work. Here's how antibacterial mouthwash interferes, and what to do instead.

Last updated October 9, 2026 • Reviewed by Dr. A. Reviewer, M.Sc. Nutrition • Based on peer-reviewed sources

Short answer: Bacteria on your tongue convert nitrate into nitrite — without them, beets do little for blood pressure.^{[Webb et al., 2008 4; Alzahrani et al., 2020 56]}

Key takeaways

✓Bacteria on your tongue convert nitrate into nitrite — without them, beets do little for blood pressure.^{[Webb et al., 2008 4; Alzahrani et al., 2020 56]}
✓Antibacterial mouthwash reduces this conversion and can raise blood pressure.^{[Kapil et al., 2013 7; Singh et al., 2026 55]}

The mouth is part of the pathway

About a quarter of the nitrate you absorb is pulled back into your saliva. Tongue bacteria reduce it to nitrite, which you swallow and convert to nitric oxide.^{[Lundberg et al., 2008 6]}

Spitting out saliva for a few hours after drinking juice removed both the nitrite rise and the drop in blood pressure.^{[Webb et al., 2008 4]}

What mouthwash does

In healthy volunteers, a week of antiseptic mouthwash reduced oral nitrite production and raised blood pressure.^{[Kapil et al., 2013 7]}

A 2026 scoping review of human studies supports that antibacterial mouthwash can interfere with blood pressure regulation, though results vary.^{[Singh et al., 2026 55]}

Practical tips

Brush and floss as normal. If you use antibacterial mouthwash, avoid it in the hours around drinking beet juice, and ask your dentist whether you need it daily.^{[Kapil et al., 2013 7; Alzahrani et al., 2020 56]}

Educational information only — not medical advice. Talk to your clinician before changing your diet or medication.

References5 peer-reviewed sourcesShow all

4.Webb AJ, et al. Acute blood pressure lowering, vasoprotective, and antiplatelet properties of dietary nitrate via bioconversion to nitrite. Hypertension. 2008;51(3):784–790. View source
6.Lundberg JO, Weitzberg E, Gladwin MT. The nitrate–nitrite–nitric oxide pathway in physiology and therapeutics. Nat Rev Drug Discov. 2008;7(2):156–167. View source
7.Kapil V, et al. Physiological role for nitrate-reducing oral bacteria in blood pressure control. Free Radic Biol Med. 2013;55:93–100. View source
55.Singh B, et al. The effect of antibacterial mouthwash on blood pressure in humans: a scoping review. BMC Cardiovasc Disord. 2026. View source
56.Alzahrani HS, et al. The role of dietary nitrate and the oral microbiome on blood pressure and vascular tone. Nutr Res Rev. 2020. View source

Claims marked [*] are awaiting a verified source.