Lifeboat Foundation

In a study published last month in mSystems, researchers from Osaka University revealed that the interaction between two common types of oral bacteria leads to the production of a chemical compound that is a major cause of smelly breath.

Bad breath is caused by volatile compounds that are produced when bacteria in the mouth digest substances like blood and food particles. One of the smelliest of these compounds is methyl mercaptan (CH₃SH), which is produced by microbes that live around the teeth and on the surface of the tongue. However, little is known about which specific bacterial species are involved in this process.

“Most previous studies investigating CH₃SH-producing oral bacteria have used isolated enzymes or relatively small culture volumes,” explains lead author of the study Takeshi Hara. “In this study, we aimed to create a more realistic environment in which to investigate CH₃SH production by major oral bacteria.”