Probiotics have become an accepted protocol in the treatment of many health problems. In an age when antibiotic overexposure has become commonplace, we often turn to probiotics to replace the good bacteria that most certainly has been lost for this reason and to help with a variety of gastrointestinal, skin or other problems. Usually we rely upon yogurt or lactobacillus supplements towards that goal. However, not all lactobacillus is the same. Since the discovery of the first lactobacillus in early part of the 20th century, there have been dozens of species discovered within the genus of lactobacillus and over 180 different strains identified within those species. Here is a timeline on the discovery of the different species of Lactobacillus.