There are studies that show their effects, but they are not sufficient to satisfy the European Food Safety Authority. It has banned companies like Yakult and Actimel from claiming in their advertising that their products promote health. These doubts are compounded by the fact that it is not always possible to know whether enough probiotic bacteria are reaching the large intestine alive. A break in the cold chain, or a person with a particularly acidic stomach or slow digestion, might kill off these microbes before they reach their intended destination.
