The throat or pharynx houses a wide variety of bacteria at any given time. Several studies have been conducted to identify the normal throat flora, the bacteria that are present in most healthy people. Some of the bacteria that live in the throat are capable of causing disease if the host becomes stressed, while others have a neutral or even beneficial role in the health of the host. To find out more about their specific throat bacteria, people can have a bacterial culture, in which a swab of the throat is taken and cultivated to see what grows.
At any given time, bacteria in the genera Mycoplasma, Mycobacteria, Neisseria, Streptococcus, Corynebacteria, Lactobacillus, and Proteus can be found in the throats of many people. Bacteria in the classes Spirochaetes and Actinomycetes are also common, as are the organisms Haemophilus influenze and Pesudomonas aeruginosa. The normal balance of bacteria contributes to the workings of the digestive system, and also acts to repel bad bacteria which might invade the throat.
Readers may recognize the names of the some of the normal throat flora. Streptococcus is a bacterial genus associated with strep throat, a throat infection caused by colonization with Streptococcus group A bacteria. Neisseria, another inhabitant of the throat, can cause meningitis in the form of Neisseria meningitidis infection, and Corynebacterium diphtheriae is responsible for diphtheria. Having these organisms in the throat does not necessarily mean that one will get sick, unless the host experiences stress or ill health which provide an opening for the bacteria.
Most sore throats and throat infections are actually caused not by bacteria, but by viruses or fungi, in the case of thrush, which is an infection caused by colonization with the yeast Candida albicans. When the balance of bacteria does get out of control and one type starts growing too quickly, people can experience a sore throat and a variety of other symptoms. A throat culture can be performed to see which organism is responsible, and antibiotics can be prescribed to restore the normal balance.
Studies on long term antibiotic usage have shown that people can disrupt the mouth and throat bacteria if they take antibiotics for an extended period of time. This, in turn, can make people susceptible to things like yeast infections, because the bacterial competition for resources is eliminated. This is one reason why medical professionals try to be careful about prescribing antibiotics, and to make sure that patients use antibiotics as prescribed to avoid long-term health problems.