This multi-action formula contains five probiotic strains providing 20 billion good bacteria, plus a prebiotic, vitamin C and zinc helping support healthy immune system function and general wellbeing. There's no need to refrigerate Blackmores Probiotics+ Immune Defence due to a specialised formulation process and packaging technology which helps prevent moisture from harming the good bacteria, helping to keep them alive. Blackmores Probiotics+ Immune Defence helps to support healthy immune system function and general wellbeing.