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. Th5 e combination of Lactobacillus helveticus LAFTI L10 and Lactobacillus plantarum SD5870 synergistically improves oral hygiene. The compositions are particularly useful against dental caries.