Revive Probiotic contains 5 scientifically supported and tested probiotic strains. This blend of tested strains was chosen due to the strains’ ability to reach the gastrointestinal tract and colonize, unlike many other probiotics on the market today. Probiotics that can cultivate once they reach their destination help balance the ratio of good to bad bacteria in gut. As the ratio becomes more balanced, gastrointestinal health improves.