The human intestinal tract contains trillions of beneficial or “good” bacteria that provide a multitude of health benefits, including keeping “bad” bacteria at bay. But certain circumstances can disrupt this natural but delicate balance, such as taking antibiotics, travelling, or being under high or prolonged stress. Enter Natural Factors Double Strength Acidophilus & Bifidus. This probiotic formula has been blended with goat's milk powder to provide an excellent environment for lactic bacteria to grow, helping to maintain normal intestinal health.