Tongue Bacteria

For most cases of uncomplicated halitosis, the root cause can be summed up in two words: tongue bacteria. Though it might be hard to believe, most of that bad smell comes from the back of your tongue where many organisms are thriving in the warm moist airless conditions.

Mouths are full of bacteria. This is normal: from the time of our birth, bacteria are getting into our mouths in food, on other objects, on hands, in water, even in the air that we take in when we breath through the mouth. Some of the bacteria that get in don't survive, but many do, and before very long, the oral cavity becomes a complex ecosystem of mixed organisms: organisms that live on the teeth, on the gums, in the throat, and even tongue bacteria. Many of these organisms are actually beneficial: they help break down food particles and mop up shed body cells. They compete with other organisms that are potentially harmful, thus protecting us from infection.

Overall, it's good thing to have a healthy population of organisms living in your mouth, and tongue bacteria are no exception. The problem comes when certain types of organisms gain a foothold and start to proliferate, producing larger populations. Chief among these are anaerobic bacteria - bacteria that live in places where there is very little or no oxygen. Anaerobes are common in the bowel, in some abscesses, in very wet places in the environment where organic material is rotting, and in the mouth.

If you think about it, bowel contents, abscesses, wet rotting organic material, and mouths all have something in common: they can smell very very bad. This is because anaerobic bacteria produce a bad smell when they break down proteins for nutrients. The process produces volatile sulfur compounds - molecules that contain sulfur that are readily dispersed into the air. Sulfur smells bad, and these compounds smell worse. The odor associated with bad breath, and with tongue bacteria, is essentially the same odor that we detest in feces and rotten eggs.

Bad breath comes from tongue bacteria simply because the tongue happens to be a great place for anaerobes to live. They flourish in all the tiny grooves between papillae and taste buds on the surface of the tongue, covered by a blanket of mucus and other non-cellular material. There, they can safely carry on the business of breaking down proteins that they find floating around in the mouth, and producing volatile sulfur compounds to make us all hold our noses.