What are probiotic cultures and how are they beneficial to health?

The term "probiotic" is derived from the Greek "pro bios" and literally means " for life". It is used nowadays to describe the health-promoting action of certain live microorganisms, the lactic acid bacteria. These bacteria are important constituents of a healthy gut flora. During their passage through our digestive tract, above all else, probiotic lactic acid bacteria have to withstand stomach and bile acid, because this is the only way that adequate numbers of them can survive to reach the intestine where they can exert their positive effect.