10 Strains, 25 Billion CFU Per Serving Plus PreticX XOS Prebiotic Promotes Regularity Probiotic-10 & Bifido Boost reinforces existing gut microflora with ten acid-resistant probiotic strains and nourishes them with PreticX, a unique xylooligosaccharides (XOS) prebiotic complex. PreticX specifically feeds and encourages the growth of Bifidobacteria and other probiotic organisms found in the GI tract, resulting in a healthy, balanced ratio of microflora that promotes intestinal comfort, regularity and healthy immune system function.