Maintain a healthy gut and immune system with Natural Factors' Critical Care Probiotic 55 Billion. Our blend of 12 scientifically-backed strains helps restore balance to your microbiome, fighting off the effects of stress, diet, travel, medications, and age. This high-potency probiotic supplement, suitable for vegetarians, features five bifidobacteria and four lactobacilli species and is shelf-stable for convenience. Take once daily for optimal gastrointestinal health.