It is estimated that half of all people have in their mouths—and elsewhere—the fungus Candida albicans. It’s ordinarily harmless, even beneficial; in fact, it is one of many microorganisms that are found in healthy people and help the body to function, while the immune system keeps them in check. However, sometimes these microflora, including C. albicans, overpower their immune cell guards and cause disease. C. albicans is responsible for diaper rash and yeast infections, but when it is in the mouth, it is called oral candidiasis, or thrush.
It’s not always clear what leads the ordinarily harmless microbe to attack. When the immune system is weakened—for example, by certain medications—that can result in opportunistic oral candidiasis. People with compromised immune systems due to AIDS or other illnesses are also at risk. Antibiotics can upset the balance of microflora, allowing the fungus to overwhelm the body’s defenses. Similarly, people with uncontrolled or poorly controlled diabetes will have more fungal growth and are more prone to thrush. The disease is also likely to affect smokers and other people with mouth dryness, since it makes it easier for infection to occur.
Thrush was named for the resemblance of the lesions to the bird. Other symptoms include pain and bleeding in the mouth, a cottony feeling, and reduced ability to taste foods. Mild cases can be treated by eating unsweetened yogurt to help restore the microfloral balance, or with acidophilous supplements. In more severe cases, anti-fungal drugs are used, though these can damage the liver. Preventing infection is also important—brushing your teeth regularly, eating sweets in moderation or not at all, and not smoking can all protect your mouth from thrush.
Recently, scientists found that polyethylene terephthalate, or PET, the material plastic bottles are made from, can be turned into an anti-fungal material that doesn’t harm healthy tissue and is particularly tough on drug-resistant microbial strains. In experiments, researchers found that the plastic itself did not lead to resistance, and was phenomenally successful against the fungus.