Oral Microbiome Imbalance May Impact Blood Pressure

Italian researchers contend that while the link between periodontal diseases and hypertension, or high blood pressure, has long been recognized, little research has been done on the correlation between blood pressure and nitric oxide-reducing bacteria. Produced in the body, nitric oxide (NO) is an important signaling molecule that plays a role in maintaining metabolic and cardiovascular homeostasis.¹

A powerful vasodilator, NO helps to ensure adequate blood flow throughout the body without the need for the heart to pump harder. So, it’s not hard to see that an insufficient level of NO might be problematic.

THE PATHWAY

To grasp how this all works, a basic understanding of the nitrate-nitrite-NO pathway comes in handy. NO is mainly produced in the vascular endothelium by cofactors, including an enzyme for L-arginine, an amino acid found in foods such as legumes and nuts. NO is then rapidly oxidized to nitrite and nitrate by oxygenated hemoglobin.^1,2

Once circulating, nitrate, contained in foods such as beets and leafy greens, is either excreted from the body or it ends up in the enterosalivary pathway. There, it is converted into nitrite by bacteria in the oral cavity and stomach, swallowed and absorbed systemically, and, ultimately, converted into NO in the blood vessels and other tissues. This kind of recycling is known as the nitrate-nitrite-NO pathway.^1,2

Because bacteria are necessary to convert nitrate to nitrite—and, through reduction, nitrite to NO, they are a crucial part of this process. Unfortunately, several factors—from smoking, aging, high cholesterol, and low oxygen, to use of proton pump inhibitors, antibiotics, antibacterial formulations, and inflammation—interfere with NO production. It’s these last two factors that point to a periodontal diseases/antiseptic mouthrinse link.^1,2

COLLATERAL DAMAGE

Antimicrobial mouthrinses are designed to kill bacterial pathogens in the oral cavity. Unfortunately, in a kind of scattergun approach, they may also kill beneficial, nitrate-reducing bacteria, which play a major role in blood pressure regulation.^1,2

In fact, numerous studies have shown an association between antiseptic mouthrinse, diminished nitrate reduction, and increased blood pressure. The upshot is that, increasingly, experts are cautioning against the overuse of antiseptic mouthrinses. Instead, they advocate tongue cleaning, probiotics, and prebiotics to restore the oral flora and normal NO functioning. By using some of these alternative methods, in conjunction with good diet and good oral hygiene, including proper brushing technique, appropriate dentifrice, and interdental aids, beneficial bacteria can be spared. This will allow the nitrate-nitrite reduction process to continue, fostering the production of NO and keeping blood pressure in check.¹

References

1. Pignatelli P, Fabietti G, Ricci A, Piattelli P, Curia MC. How periodontal disease and presence of nitric-oxide reducing oral bacteria can affect blood pressure. Int J Mol Sci. 2020;21:7538.
2. Blot S. Antiseptic mouthwash, the nitrate–nitrite–nitric oxide pathway, and hospital mortality: a hypothesis generating review. Intensive Care Med. October 16, 2020. Epub.