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German Research Foundation funds Freiburg project to discover new oral bacteria for periodontitis

Thousands of different bacteria live in the mouth, many of which are still unknown. Researchers at the Medical Center - University of Freiburg are now using a new approach to find out which of these microorganisms play a role in gum diseases such as periodontitis. The new project combines two methods that have been used very successfully in gut microbiome research. They are used to investigate both genetic information and the bacteria themselves. The aim of the project, which is funded by the German Research Foundation (DFG), is to gain a better understanding of how the balance of oral flora changes during illness.

"We want to better understand the diversity of bacteria in the mouth and specifically cultivate species that were previously only known by their gene sequence," says Prof. Dr. Ali Al-Ahmad, project leader and laboratory head of the Department of Operative Dentistry and Periodontology at the Medical Center - University of Freiburg.

Methods from intestinal research

At the beginning of the year, the Freiburg scientists discovered a new bacterium, Dentiradicibacter hellwigii, in a human root canal. The discovery highlights how little research has been done into the microbial world of the oral cavity.

For the DFG-funded project, physicians are taking samples from the mouths of patients with and without periodontitis. The researchers cultivate the bacteria on numerous different culture media, a process known as culturomics. At the same time, the genetic material of the bacteria is examined. The combination of these two approaches has so far been used primarily to elucidate the gut microbiome and has led to the isolation of many previously unknown bacteria.

"There are still many bacteria in the mouth that we don't know whether they protect us or make us ill. This project is an important step towards shedding light on this issue," says Prof. Dr. Fabian Cieplik, Medical Director of the Department of Operative Dentistry and Periodontology at the Medical Center - University of Freiburg.

Image1: Prof. Dr. Ali Al-Ahmad (left) and Prof. Dr. Fabian Cieplik examine the sample of an oral bacterium under the microscope.

Image2 : New developments in classical culture techniques have made it possible to study bacteria that were previously almost impossible to cultivate in the laboratory.

Image source: Medical Center - University of Freiburg