Bacteria in Your Mouth Make a Stink (and what to do about it)

Just like humans, the bacteria in your mouth consume food and then pass gas (technically speaking, they poop first, but that waste turns into a gas quickly). So we don’t merely breath out carbon dioxide, rather, each time we exhale some of that bacterial stench gets released from our mouths, too. At low concentrations the smell is undetectable, but the more those tooth, tongue, and gum dwelling microbes are able to eat, the smellier their farts and, by extension, the worse your breath.

Sadly, there is no way to stop oral bacteria from tooting altogether, but there are steps you can take to reduce the concentration of the gas that they pass so that no one will ever know.

First, let’s take a look at look at what causes oral flatulence.

There are lots of bacteria in the human mouth, both good and bad, which consume food and then excrete waste byproducts.

Many of those anaerobic (preferring environments devoid of oxygen) microorganisms poop out stinky sulfur compounds like hydrogen sulfide, the same mixture of elements responsible for the stench of rotten eggs, and methyl mercaptan, which is what you’re probably smelling when you pass an animal feedlot.

Dentists refer to much of the waste excreted by oral bacterial as “volatile sulfur compounds,” (VSCs). These compounds are considered “volatile” because they transform from a solid into a gas rapidly, even at ordinary temperatures. That’s why your breath can get so stinky so fast.

VSC’s are mostly to blame for bad breath, but not entirely.  Oral-dwelling bacteria also produce compounds like cadaverine, putrescine, skatole, butyric acid, indole, and isovaleric acid. This bunch can also be found in the odors of urine, rotting meat, human feces, sweaty feet, and vomit.

As many as 500 bacterial species reside in your mouth, and most of them are capable of producing rotten smells.

Thankfully, those gases, while often present, are generally undetectable in your breath. But the worse your dental hygiene, then the higher the chance that the concentration of any of those compounds will increase to a detectable, unpleasant level.

How to Keep Mouth Farts at Bay

Try as you might, there is no known way to completely stop the bacteria in your mouth from excreting smelly waste. But there are plenty of ways to control the number of these bacteria that live inside your mouth.

1. Beware of Plaque

The accumulation of plaque, a sticky, whitish deposit of gunk on the teeth, creates an ideal environment for odor-causing bacteria. Remember, those bacteria thrive in oxygen-depleted environments. Even a film of plaque thinner than a dollar bill is enough to create an almost entirely oxygen-free habitat. Allowing plaque to build up is akin to letting waste in your trash bin overflow — over time, it’s going to smell. So make sure to floss and brush regularly.

2. And Tongue Plaque, too

Plaque also forms on the tongue, so make sure to brush your tongue, not just your teeth! Up to four times as many bacteria attach to skin cells on top of the tongue than anywhere else in the mouth, And as more plaque coating builds up, bacteria gain more access to hospitable living space. 

3. Brush After Eating

When you eat, so do the bacteria in your mouth. That shouldn’t stop you from eating, but it should encourage you to brush your teeth (and your tongue) as soon as you can after meals.

4. Stay Hydrated

When you don’t drink enough water the oral tissues in your mouth can dry out, creating a sensation known as “dry mouth.” A decrease in oral moisture reduces the ability of saliva, the body’s natural mouth rinse, to dilute and wash oral bacteria. 

5. Talk Less

People who speak for long periods of time (lawyers, teachers, politicians, etc.) should be extra diligent about hydrating. The more you talk, the drier your mouth gets, and therefore the more likely you are to experience bad breath.

6. Unless it's With Your Dentist

If you practice good oral hygiene but still suffer from bad breath, talk to your dentist. Many other dental and medical conditions could be the culprit, many of which can be diagnosed and treated with a simple visit to the dentist’s office.