The entire human body is a habitat for other, smaller living creatures — bacteria. They live on the skin’s surface, in the gastrointestinal tract, and on the mucous membranes of the body, including in the mouth.
What Do Bacteria Have to Do With Bad Breath?
Anything alive must eat, and, as a result, generate waste products. It is actually the metabolic waste products of bacteria that cause most cases of bad breath, clinically known as halitosis. The metabolites of some bacteria contain sulfur, a foul smelling element that stinks like rotten eggs. These sulfur-containing waste products, called volatile sulfur compounds (VSCs), rapidly evaporate into the vapor of bad breath.
What Type of Bacteria Live in the Mouth?
The oral cavity is colonized by a variety of microbes that live in the mouth full-time. Gram-positive Streptococcus, Actinomces, Lactobacillus and Gram-negative Veillonella and Neisseria are first on the scene, present before a baby even cuts his or her first teeth. Once a person has a set of teeth for bacteria to hang on to, Streptococcus parasanguis and S. mutans, bacteria with a slimy outer glycocalyx, form biofilms, and are able to attach to the tooth’s enamel surfaces. Another type of Strep, S. salivarius attaches to the surface of the mucous membrane in the mouth and colonizes the saliva.
How Bacteria Create Bad Breath and Other Unpleasant Body Odors
Biofilms are sticky layers produced by some bacteria. Biofilms help these bacteria adhere to surfaces, and slowly buildup. In the mouth, this buildup is plaque, a hard layer on the teeth that creates conditions ideal for formation of cavities. The accumulation of plaque creates areas near the tooth surface where oxygen is unable to penetrate. Certain oral bacteria thrive in oxygen-free (anaerobic) environments. They are the ones that create the sulfur-stinking waste products; the more plaque, the more potential for bad breath.
The content of an organism’s waste is obviously related to what it consumes, and these anaerobic bacteria especially like feasting on protein products. Bacteria consuming protein create more VSCs (volatile sulfur compounds). Bacteria-generated sulfur compounds not only make breath stink, but are also the general type of chemical that causes the stink at the other end of the GI tract, the bad smell of feces and intestinal gas.
Although cutting back on consumption of protein products can reduce the stink, bacteria have plenty of sources of protein other than the human diet. The dead cells shed by the body’s mucous membranes contain protein as well.
How to Fight Bad Breath, Reduce Halitosis
The bacteria in the mouth that cause bad breath live mainly at the back of the tongue and under the gum line. The best way to keep breath smelling sweet is to maintain good oral health, brushing teeth and tongue well first thing in the morning, before bed and after every meal. Brushing removes bacteria over the short-term and also prevents the build-up of plaque. When unable to brush, chew gum; it increases the amount of enzyme-containing saliva in the mouth, which helps to temporarily reduce the number of bacteria. Cinnamon gum is best, since cinnamon oil has an added antibacterial benefit.
For more information on oral health, see:
- WebMD: Bad Breath Causes, Treatments and Prevention
- Bad Breath: Gastrointestinal Problems and Halitosis
Tami Port - Tami Port is a college professor of cell and microbiology and creator of ScienceProfOnline.com, a free science education website.
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