Finding New Human Mouth Bacteria

Your mouth does a pretty good job of providing a cosy home for millions of microbes - bacteria, viruses, fungi, and protozoa. It really is a jungle in there and it's been estimated that half of the bacterial strains are unknown.

Although we happily co-exist with many of our microbial tenants some are problematic, being the root causes of mouth problems such as gum disease and tooth decay.

Expeditions to find mouth bacteria and then classify these little beasties are important first steps in finding new ways of improving oral hygiene. Bacteria are by far the most numerous mouth microbes.

The Human Oral Microbiome Database is a comprehensive list of the 600 or so mouth bacteria species. It contains their descriptions and tools for the analysis of their DNA.

In 2008 scientists from the Dental Institute at King's College London found three new strains of a bacterial organism lurking inside the flesh lining the mouth. They called it Prevotella histicola and the name "histicola" is of Latin origin, meaning "inhabitant of tissues". Other members of the Prevotella "family" have been previously linked to oral diseases, as well as infection in other body locations.

The new species was found in both normal healthy cells and oral cancerous tissue. The scientists involved in the research said this confirmed that oral bacteria can invade tissues as well as individual cells.

Most strains of mouth bacteria are good for us and are believed to play important roles in maintaining oral health. The potentially disease causing bacteria are in the minority, but even so tooth decay and gum disease are the most common bacterial diseases in humans.

Therefore understanding the problems they cause is imperative as scientists search for better treatments, although this kind of research is sometimes hampered by the fact that mouth bacteria can be quite difficult to grow in the lab.

However, the researchers will not be put off as further expeditions and investigations into the many unrecognised bacterial species are needed - particularly if some of those have the capacity to cause disease.