Nature's Bounty Optimal Solutions Controlled Delivery Probiotic is an easy way to get the digestive and intestinal support you need. These caplets feature Bio-tract technology, which allows the caplet to pass through the digestive tract and release live organisms at targeted locations within the digestive system. Regular enteric coating protects Probiotics from stomach acid. Controlled Delivery Probiotic works differently than regular enteric coating-it not only protects your probiotics from the harsh environment of the stomach, but delivers them continuously during the day to various parts of your digestive tract A large percentage of your bodys immune system cells are contained within your gastrointestinal tract. Probiotics help maintain healthy intestinal balance, providing support for immune health. A healthy digestive tract helps maintain overall immune system health.