It might not be the garlic or onions, coffee or alcohol. Rather, a new study links it to the types of bacteria that dominate the back portion of the top of your tongue.

• 研究发现，口腔异味并不一定是因为大蒜、洋葱、咖啡或酒精引起的，罪魁祸首有可能是位于舌尖背部的几种特殊类型的细菌。