New research, published in the journal Frontiers in Cellular and Infection Microbiology, shows that an antiseptic compound found in mouthwash destroys “friendly” oral bacteria that help maintain normal blood pressure levels.

New research finds that mouthwash could destroy ‘friendly’ oral bacteria, which may have important consequences for a person’s cardiovascular health.

Scientists know that the bacteria in our guts influence overall health, but perhaps less obvious is the connection between oral bacteria and a variety of health conditions.

For instance, Medical News Today recently reported on a range of studies that linked gum disease and the buildup of certain bacteria in the mouth with Alzheimer’s disease, cardiovascular disease, and respiratory conditions.

Another recent article showed how a specific oral bacterium could speed up the progression of colorectal cancer and make the disease more aggressive.

These studies focused on bacteria that cause disease, but, just like our guts, our mouths also contain “friendly” bacteria, which are necessary for maintaining good health.

An oral microbiome with a good balance between these different kinds of bacteria can keep disease at bay. Studies have found that when this balance is upset it “contributes to oral and whole-body systematic diseases” as diverse as inflammatory bowel disease, Alzheimer’s, rheumatoid arthritis, obesity, atherosclerosis, and diabetes.

New research points out that a balanced oral microbiome helps maintain good cardiovascular health by helping the conversion of dietary nitrate into nitric oxide (NO) — a signaling molecule that helps maintain normal blood pressure.

Worryingly, however, the new study shows that chlorhexidine, an antiseptic substance in mouthwash, may kill NO-producing bacteria, which in turn, may raise systolic blood pressure.

Nathan Bryan, Ph.D., from the Department of Molecular and Human Genetics at Baylor College of Medicine in Houston, TX, led the new research.