Probiotic compositions, particularly oral compositions, comprising one or more bacteria that are capable of producing nitrite and/or nitric oxide in a subject are provided. Some compositions further comprise nitrate/nitrate, such as a botanical source of nitrate. Some compositions further comprise botanical sources of nitrate reductase. Also, provided are methods of improving the oral and/or vascular health of a subject by orally administering a composition comprising one or more bacteria capable of producing nitric oxide. Methods of repopulating the nitric oxide producing microflora and bacterial environment in the oral cavity of a subject are also provided.
