We know the bacteria in our gut controls a lot more than just keeping our intestinal systems healthy, but what about the bacteria in our mouths? A 2019 study points out that using an oral, antibacterial mouthwash can affect your blood pressure and how your body reacts after a workout.
While you exercise, due to the dilation of blood vessels, your body produces more nitric oxide, and after you’re done exercising, blood pressure is lowered in a phenomenon called post-exercise hypotension. Though the exact mechanisms of this are unknown, some researchers have found evidence to believe it is due to oral bacteria and its role in recycling the nitric oxide and byproducts after exercise.
Nitric oxide produces a byproduct called nitrate, which oral bacteria break down into nitrite. Some of the nitrite gets taken up again by the body after we swallow it in our saliva, and the nitrite is then turned back into nitric oxide, which keeps the blood pressure lower. Researchers believe that the reason why we experience low blood pressure even hours after exercising is because of this cycle.
To test their hypothesis, researchers asked healthy participants to exercise and have their blood pressure monitored afterwards for a period of two hours. Half of the participants were given an antibacterial mouthwash, while the other half were given a placebo mouthwash with no antibacterial properties.
In the group of participants who were given the antibacterial mouthwash, their blood pressure wasn’t lowered to the same degree that the placebo group experienced. After the two-hour post-exercise period had passed, the antibacterial mouthwash participants did not have any post-exercise hypotension effects left at all. The mouthwash directly reduced the saliva’s ability to make nitrite, and there were lower levels of nitrite in blood and saliva samples.
On the other hand, the group which was not given a mouthwash that would kill off any oral bacteria experienced lowered blood pressure and were still experiencing post-exercise hypotension at the two-hour mark.
Even though this research won’t affect how you exercise or use mouthwash, it provides the potential for more research about oral health and the oral microbiome and how it relates to cardiovascular health. It’s well known that gum disease and poor oral health can contribute to cardiovascular disease. It may be possible to use studies like these to populate the oral microbiome of compromised individuals with the right type of bacteria to help control blood pressure.
- Cutler, C., et al. “Post-Exercise Hypotension and Skeletal Muscle Oxygenation Is Regulated by Nitrate-Reducing Activity of Oral Bacteria.” Free Radical Biology and Medicine, vol. 143, 1 Nov. 2019, pp. 252–259., https://doi.org/10.1016/j.freeradbiomed.2019.07.035.