Research into the oral microbiome and e-cigarettes is starting to reveal the consequences of vaping

The minty flavors of vape juice might temporarily cover up bad breath but the root cause of halitosis is a bacterial imbalance, which is made worse by the habit of smoking electronic cigarettes.

As long as vaping continues, helpful oral bacteria are killed off, weakening the body’s defenses against bacteria that cause tooth decay and bad breath. In fact, there’s a systemic cascade of disease associated with the destruction of certain tiny organisms that live in the mouth. Decaying teeth and offensive breath are signs of bigger problems, and even top-notch oral hygiene habits cannot overcome damage created by dysbiosis, an imbalance of bacteria.

“Somewhere along the line, somebody convinced them that vaping is safer than smoking. But safer is not safe,” said Dr. Elle Campbell, a family integrative physician. “There are really negative side effects to vaping.”

She may not be a dentist, but Campbell and other doctors that make up the American Academy for Oral & Systemic Health are educating themselves about the connection between oral health and disease for their patients’ sake. And they are raising alarm about vaping, which became popularized after Chinese pharmacist Hon Lik patented the first e-cigarette, in 2003. 

While Lik’s intentions were benign—his dad was a heavy smoker and died of lung cancer, motivating him to develop a less-harmful alternative—long-term research was lacking. On top of that, two decades of evolving science includes revelations on the vital role of the microbiome in oral and overall health.

Meanwhile, the e-cigarette industry exploded on the premise of “safer,” which has never been proven. Proliferation of a wide variety of products has gone largely unmonitored, creating unknown complications for users and layers of complexity for scientists who are trying to contextualize harm.

E-cigarettes fit in the palm of the hand, sometimes so small they’re easily hidden, and use a battery to heat up a liquid solution (vape juice) in order to produce an aerosol. They can be activated by a button or by inhaling. Nicotine, tetrahydrocannabinol (THC), and cannabinoid (CBD) oils can all be used in vapes. These solutions can contain any number of carcinogens and toxicants.

Despite many unknowns, there are plenty of facts including studies about the impact on the microbiome—the colony of microorganisms including bacteria that live in and on the body—that tell a compelling story.

How Vaping Kills Microbes

Vaping assaults the oral microbiome with chemicals, additives, and sweeteners that stick to the teeth. It can damage the enamel and kill off the healthy bacteria that stem the tide of plaque.

Mouths are full of flora that keep the environment balanced by killing off pathogenic invaders. It’s a system that works relatively well unless it’s thrown off balance by toxins—chemicals, medications, and sugary, processed foods that are associated with low levels of healthy bacteria.

“We have to have bacteria in our mouth. They’re the good guys,” Campbell said. “They keep our gums and our tissues strong and healthy. If there was no bacteria in our mouth, we’d lose all our teeth.”

Too much bad bacteria also causes bad breath. That same imbalance associated with halitosis causes periodontal disease as well as mouth and digestive cancers, according to a 2020 study published in the Journal of Clinical Medicine.  Periodontal or gum disease damages the soft tissues of the mouth and can lead to tooth loss.

Smoking cigarettes already increases one’s chances of gum disease fourfold, and research has established that periodontitis is associated with a pathogen-rich oral biome. But as one 2020 study published in Science Advances pointed out, it can take more than a decade for visual signs of periodontal disease to manifest.

The article stated there’s reason to believe oral microbiome changes happen earlier in vaping than in smoking and there are other mechanisms that vary from smoking, warranting more extensive studies. “…e-cigarettes have the potential to shift the host-microbiome equilibrium, posing a significant risk for future disease,” according to the article.

Among the estimated 5.66 million adults who currently vape, 23 percent didn’t smoke previously, and most were younger than 35 according to the Journal of the American Medical Association.

A study published in early 2022 in Molecular and Oral Microbiology showed a six-month shift in the oral microbiome of 101 e-cigarette patients. Their bacterial composition more closely resembled that of smokers, including high numbers of periodontal-disease-associated pathogens and proinflammatory cytokines all indicative of microbiome dysbiosis and advanced disease. A study that came out in November in the Journal of the American Dental Association validated the relationship between vaping and tooth decay.

How it happens isn’t explicitly clear but could be linked to several factors that are unique to vaping, including the temperature of the aerosols that penetrate the protective biofilm on the teeth. Vaping also has a more alkaline pH, as well as unique properties such as heated metals that sometimes turn up in the aerosol and propylene glycol, which is generally considered safe in food but is known to damage enamel and lower saliva levels.

E-juice typically contains four ingredients: nicotine, water, flavoring, and propylene glycol or vegetable glycerin (or both). The solution itself can contain toxins, and the heating process can also create a unique thermal decomposition of toxic compounds. A January 2022 review in Toxins found various studies showing toxicants such as carbonyls, formaldehyde, acetaldehyde, acrolein and more. Other studies have found additional contaminants, like dangerous chemicals used in pesticides, metabolites commonly found in blood and feces, and endotoxins.

The aerosol toxins can also alter the immune system in harmful ways. Oral pathogens can then sneak in under lowered defenses and cause inflammation of the gums, bleeding, and gum pockets that allow pathogens to seep in further and cause decay in the teeth and gums. Redness, swelling, and bleeding are signs of periodontal disease.

Damaging the Whole System

Not only is the structure, health, and appearance of the mouth under attack from dysbiosis, but the imbalance opens the door for pathogens to invade the entire body.

“What happens in the mouth doesn’t stay in the mouth. It goes everywhere,” Campbell said. “As a family doctor, the reason I’m concerned more is that those very same bacteria increase our risk for heart attack, stroke, cancer, diabetes, and Alzheimer’s disease. These bacteria get in our bloodstream and once they’re in our bloodstream, all bets are off.”

Even though the gut and mouth have separately unique microbiomes, individual microorganisms can travel both ways as demonstrated in a September, 2022 Clinical Science study.

A periodontist and certified functional medicine practitioner, Dr. Alvin Danenburg said pathogens can compromise the body in numerous ways, but the damage can also be reversed when smoking ceases.

“You can’t stop the mouth infection without addressing the gut, and you can’t stop the gut infection without addressing the mouth because they communicate back and forth,” he said. “The beautiful part of this is both are very treatable.”

In addition to quitting vaping, Danenberg said getting adequate sleep, improving diet, being mindful of chemical exposure, exercising without overdoing it, and addressing stress can all help balance the microbiome.

More Evidence to Warn Kids of Vaping

Teenagers and young adults, who tend to eat more sugar-laden diets, are particularly at risk from a collision of unhealthy habits impacting the microbiome. One in four students vapes, according to 2019 data from JAMA. They’re also the target of a lot of misleading messaging.

“It’s not their fault,” Danenberg said. “When the industry tells us this is a great alternative to cigarette smoking and it tastes good and it’s harmless, you know why not. The sad thing is the research is just starting now.”

Many e-cigarette liquids were found to contain aldehydes, toxins related to sugar, and high sucrose levels, according to a 2018 study in Nicotine and Tobacco Research. 

“Because sugar added to tobacco alters the smoke in cigarettes by modifying sensory impact of nicotine and other tobacco alkaloids, it is possible that sugar in e-cigarettes may make the product more appealing,” researchers wrote. “Furthermore, most product labels did not list sugars or provide warnings about aldehydes on the labels.”

Campbell said young people should tell healthcare providers about their lifestyle choices and risk factors and ask for oral cancer screenings. She advocates for parents to have their children use oral hygiene products, gum, and mints containing xylitol. While not a substitute for quitting vaping, good oral care, or a healthy lifestyle, there’s evidence that xylitol can help protect against cavities.

Overcoming addiction isn’t easy, and nicotine is highly addictive because of how fast it enters the bloodstream and the euphoria users get when dopamine levels rise. Only about 6 percent of smokers are able to quit each year, according to the U.S. National Institutes of Health.

“There’s lots of reasons people might want to pick nicotine,” Campbell said. “But there’s other stuff in that vaped chemical. They’re exposing their body to a toxic burden that they may not have appreciated.”

Vaping is clouded with mixed messages, not unlike cigarette marketing from 80 years ago. An advertising campaign in 1946 featured the slogan, “More doctors smoke Camels than any other cigarette.”

Danenberg is concerned there may be even greater harm associated with vaping compared to cigarette smoking.

“Eventually science caught up with them and figured that smoking was unhealthy. Look how many years it took for that to happen,” he said. “It’s going to take a long time to get the research that’s published and being actually investigated today to the clinicians like dentists and physicians to let them know to get their patients information.”