Sugarless yoghurt could help beat bad breath, tooth decay and gum disease, say scientists.

　　Japanese researchers found eating the yoghurt reduced levels of hydrogen sulphide - a major cause of bad breath - in 80% of volunteers.

　　The key are active bacteria in yogurt, specifically Lactobacillus bulgaricus and Streptococcus thermophilus.

　　Details were presented at a meeting of the International Association for Dental Research.