Compositions for use in oral hygiene contain a Lactobacillus helveticus strain. Compositions further containing a Lactobacillus plantarum strain, especially Lactobacillus plantarum SD5870, are particularly effective. The combination of Lactobacillus helveticus LAFTI L10 and Lactobacillus plantarum SD5870 synergistically improves oral hygiene. The compositions are particularly useful against dental caries.