Hello dear,my name is dr,Dorina Gurabardhi.I understand your concern. Enterogermina is a very helpful probiotic which contains Bacillus Clausii, which is a kind of bacteria. Our digestive system or out gut contains many helpful bacteria. They help us in many different ways and protect us from harmful bacteria attacking our body. A probiotic is a substance which contains many helpful bacteria like lactobacillus, Bacillus Clausii. They promote the growth of helpful bacteria in our gut. Hope my answer was helpful,if you have any other question I will be glad to answer,thanks!