Primal Defense is the only probiotic formula that contains a unique whole food blend with Homeostatic Soil Organisms (HSOs). The HSOs in Primal Defense are important probiotics because most fruits and vegetables that we eat have been sprayed with pesticides. The food loses the probiotics when they are treated with chemicals. To replenish the valuable probiotics our pasteurized, irradiated and disinfected food no longer provides, Primal Defense includes 12 species of hardy beneficial microorganisms in the form of the HSO Probiotic Blend. Let the unique HSOs in Primal Defense take you to a new level of total health.