The reduction in the risk of pre-cancerous bowel growths in men who ate 490g or more live yogurt a week (around four small pots). Researchers suggest one reason for the effect may be that two types of the live bacteria in yogurt, Lactobacillus bulgaricus and Streptococcus thermophilus, may help lower the number of cancer-causing chemicals in the gut. The findings were based on a study of more than 32,000 men.