A potent probiotic blend, Dr. Stephen Langers Ultimate Probiotic with Fos features sixteen strains of probiotics and 3.2 billion Cfu per capsule to promote digestive health. That's four times the number of strains and over twice the CFUs in many popular probiotic formulations, and while other probiotic combination supplements contain only two strains of Bifidobacteria, Dr. Langers formula delivers five. This ultimate 16-strain probiotic formula also contains ten strains of Lactobacillus, including Lactobacillus reuteri, which has a unique affinity for promoting colon health and immune system function, along with prebiotic Fos (Fructooligosaccharides) and ConcenTrace trace minerals. Fos are oligosaccharides that deliver a prebiotic effect. Trace minerals are a vital part of the enzymatic process necessary for healthy digestion and are lacking in the diets of many people.