It is important to realize that fermented foods are not “the same thing as probiotics”, and here are some reasons why:
Not all fermented foods contain live microorganisms.
Beer and wine for example have gone through a filtering process in which the microbial organisms (such as yeasts) are removed. In other foods, such as sauerkraut and bread for example, the microorganisms are exposed to high temperatures and die during the cooking process.
Not all bacteria are probiotic
The bacteria present in non-heated or filtered fermented foods, such as dry fermented sausages, cheeses and kimichi, do contain bacteria but these cultures do not necessarily have a probiotic function. The definition of a probiotic bacteria is that it must confer a health benefit for the host, and the bacteria present in these types of foods must have been classified as such. For some dairy products it can be the case that the bacteria responsible for the fermentation process are characterized as probiotic which is often the case for many yoghurt cultures.