The Fungus in Your Mouth

A dentist will tell you, mouths are teeming with microbes, bacteria and fungus – yes, fungus. It’s a perfectly balanced mix but when disrupted, leads to oral disease. A study cataloging the core oral bacteriome (the bacteria commonly present in our mouths) and the core oral mycobiome (the fungi commonly present in our mouths) was published in March of this year in PLOS Pathogens, a peer-reviewed open-access medical journal about pathogens and how they interact with their host organisms. Researchers compared the bacteria and fungi present in the mouths of healthy individuals with those from patients infected with HIV. HIV patients, or anyone suffering from an autoimmune disease are particularly susceptible to fungal infections. Mahmoud Ghannoum and his colleagues at Case Western Reserve University in Cleveland, Ohio found little difference between the bacteria found in the mouths of health individuals and those with HIV. The fungi, on the other hand, showed clear and consistent differences.

Common Microbes

Candida, a family of fungi also known as yeast which is always present in the mouth, digestive tract and skin, can be thrown off balance by certain illnesses like HIV causing thrush. The term thrush specifically refers to babies with oral fungal infections caused by Candida albicans. The term is often used to describe all oral fungal infections in adults which are more properly named candidiasis or moniliasis. Researchers confirmed Candida was present at higher levels in HIV-infected individuals. But one little-known fungus called Pichia was found to have interesting characteristics. The mouths of healthy individuals were found to contain fairly high levels of the fungus Pichia, whereas those individuals infected with HIV were found to contain lower levels. This led researchers to seek out the connection between the two. Ghannoum’s team found that mouths that contained more Pichia tended to have lower levels Candida. The researchers then studied the two microbes by incubating them together and found that together, Pichia flourished and Candida withered. This could explain why people with HIV are more susceptible to thrush.

New Treatment for Thrush

The team suspected that Pichia produced a chemical that poisoned Candida so they filtered out the fungal cells from the Pichia cultures. What was leftover proved to be a powerful antifungal and when given to mice with Candida infections, the “Pichia spent medium” (or PSM) concoction killed the Candida. This new Pichia-based treatment outperformed even the standard treatment for thrush, nystatin. “This is a tremendous advance in the field,” says Anna Dongari-Bagtzoglou, an oral microbiologist at the University of Connecticut Health Center in Farmington. Besides being the first study of the fungal microbiome in people with HIV, it’s also the first study that compares bacterial and fungal populations in the same patients, she says. “These correlations are important because for many years we thought the two kingdoms were in competition,” she says, adding that research from her lab has shown that some bacteria can even combine with Candida to make infections more severe. Ghannoum and his team say, “Our findings have wide implications regarding the discovery of novel antifungal agents and will open the way to new therapeutic approaches for the management of fungal infections.” They continue, “Detailed investigations are warranted to purify and characterize the specific Pichia factor(s) that can inhibit Candida and other disease-causing fungi.”

Dental Patients and Fungi

Fungal infections from Candida can make the mouth extremely sensitive. This sensitivity can interfere with normal dental hygiene causing additional tooth decay problems. If you are experiencing mouth sensitivity from a possible fungal infection you might try rinsing your mouth with a diluted Hydrogen Peroxide solution and using a soft toothbrush. Book an appointment with Dr Andrew Hall at his Colorado Springs office if you have any questions about your oral health, even a fungal infection. He will be able to identify a problem, give recommendations on mouthwashes or other treatments or refer you to a specialist for additional diagnosis and treatment.