Bifidobacteria Longum with Lactobacillus and Oligosaccharide Seamless Microcapsule Delivery System Seamless Triple Layer Encapsulation Delivers Living Friendly Bacteria to the Large Intestine Easy to Use Non GEO Derived Refreshing TasteEden Bifa-15 is the Ultimate Probiotic. Each ingredient enhances the development of the dominant species in the Bifa-15 formula, bifidobacteria, the most important "friendly" bacteria that resides in the large intestine. Bifa-15 releases only when it gets to exactly the right spot in the digestive system.One tube of Bifa-15 contains three billion living bacteria protected from stomach acids by tiny 1mm, easy to swallow capsules. Granules of refreshing oligosaccharides are the specific food the bifidobacterium need to thrive.