Halitosis or bad breath is caused due to the accumulation of anaerobic bacteria. These bacteria are strict anaerobes and they cannot survive when the atmospheric oxygen is present. Bad breath coming from the sinus cavity, throat, mouth or stomach is all caused by these odors causing anaerobic bacteria.
(1) Where do anaerobic bacteria live and what can they cause?
Anaerobic bacteria causing bad breath are not only present in the mouth, but they are also widely occupied in the sinus cavity, stomachs, throat, intestines, lungs, and lymph nodes. Infections in these organs and regions can cause varying degrees of bad breath. For example, excessive growth of stomach bacteria in the esophagus can lead to acid refluxes, causing bad breath.
However, in most of the people who suffer from chronic halitosis, anaerobic bacteria that cause bad breath is frequently found inside the mouth.
(2) Tongue – the location for anaerobic bacteria
A lot of the odor-causing anaerobic bacteria lives on the tongue surface and also below the tongues. Other areas that foster bacteria include gum lines (in and around the teeth) and in-between the teeth.
Food particles can get lodged in between the teeth and these places are hard to clean merely by brushing. Hence, food debris that is lodged in gives ideal place for anaerobic bacteria to accumulate and live.
Anaerobic bacteria that cause bad breath can find an anaerobic environment to live and survive even under the gum lines, that is, in and around the teeth. People with gum diseases, foster these anaerobic bacteria in their gum line because gum diseases (periodontal diseases) cause the gums to fade away from the teeth causing periodontal pockets. These pockets serve as a shelter for anaerobic bacteria which causes bad breath.
(3) Imbalances of good and harmful bacteria
The imbalance between bad and good bacteria in the sinus cavity, mouth, throat, and stomach can lead to excessive growth of harmful bacteria. This imbalance of bacteria allows larger colonization of bad breath causing bacteria, hence, volatile sulfur compounds (VSCs) are more produced resulting in bad breath.
(4) Food source for anaerobic bacteria that causes halitosis
Anaerobic bacteria most often eat proteins ingested by individuals. Therefore, protein foods cause bad breath indirectly. An individual’s diet consists of protein foods like fish, eggs, meat, cereals, nuts and dairy foods. Hence, when you eat these proteins, bacteria also get a portion of the meal.
Protein maximizes the metabolic activity of these anaerobic bacteria in the mouth. However, they can also feed on other types of food. Leftover food debris in the teeth and gums provide nutrients continuously for bacteria to feed, flourish and thrive.
The breakdown of protein food particles in the mouth stuck between the teeth produces these compounds. Due to these waste products of bacterial metabolism, rotten egg smell or sour smell comes out through the mouth while breathing out.
(5) How anaerobic bacteria cause bad breath
Bacteria also consume nutrients present in the food and excrete out waste products as by-products. These by-products of bacterial metabolism are certain kinds of volatile sulfur compounds (methyl mercaptan, dimethyl sulfide) and hydrogen sulfide (rotten egg smell). Other waste products released by the anaerobic bacteria that live in the mouth involves:
- Skatole (smell like human feces)
- Cadaverine (corpses smell)
- Putrescine (decaying meat smell)
- Isovaleric acid (sweaty feet smell)