# Probiotic Strains: A Deep Dive into CFU Counts and Efficacy The probiotic market is flooded with products making bold claims, but what does the science actually say about CFU counts, strain specificity, and clinical efficacy? ## Strain Specificity Matters Probiotic effects are highly strain-specific. Different strains of the same species can have completely different effects. ## Optimal CFU Counts Digestive Health: 10-20 billion CFU daily. Immune Support: 25-50 billion CFU daily. Post-Antibiotic Recovery: 50-100 billion CFU daily.