Abstract: Mouth hygiene compositions that reduce VSC by changing the growth conditions in the oral cavity in favor of bacteria capable of anaerobic respiration. Anaerobic respiration is a form of respiration that involves electron acceptors other than oxygen. Examples of such alternative electron acceptors are sulfates, nitrates, sulfur and fumarate. A shift towards anaerobic respirational growth of the microflora in the oral cavity is brought about using an oral hygiene composition that is rich in nitrates. Such a composition considerably reduces the production of VSC compounds, especially hydrogen sulfide. Moreover, it has been established that by using these oral hygiene compositions, the overall diversity of the mouth flora is not diminished, but rather shifted from an halitotic (strictly anaerobically growing) bacterial population to a less halitotic one. The compositions are suitably used to treat and/or prevent halitosis in mammals.