Digesta-Lac® is step three in Natren's three-step custom probiotic system. This Lactobacillus bulgaricus probiotic supplement provides support throughout the digestion process*. Natren's Lactobacillus bulgaricus LB-51 super strain is a transient beneficial bacteria that travels through the digestive tract with food through the process of digestion. Each serving of Digesta-Lac® provides a minimum of 2 billion colony forming units (cfu) of Lactobacillus bulgaricus LB-51 transient super strain. Dr. Elie Metchnikoff, a Nobel Prize winning scientist who theorized that aging is caused by toxic bacteria in the gut, linked the oft-noted longevity and good digestion of the Bulgarian people to the large quantity of fermented milk products containing Lactobacillus bulgaricus in their diet.