With Clinically Documented Strains4 Bifidobacteria Probiotic StrainsProbiotic SupplementVegetarian5 Billion Per CapsuleStrains Matter™: Jarrow Formula's Probiotic Contain Documented StrainsBifidus Balance® + FOS promotes healthy intestinal microfloral balance by providing four species of the genus Bifidobacterium. Bifidobacteria are the predominant, beneficial bacteria residing in the colon. FOS is a natural prebiotic fiber that enhances the growth of beneficial probiotic bacteria.