Probiotics and prebiotics are important for human health. Probiotics are live bacteria that can provide various health benefits, and are found in certain foods or supplements. Prebiotics are substances that come from certain types of carbohydrates that humans cannot digest, but are food to the beneficial bacteria in the gut. The gut bacteria are jointly called gut microbiota and perform many vital functions in the body. Eating balanced amounts of both probiotics and prebiotics can help maintain the right balance of these bacteria. Gut microbiota gives protection from harmful bacteria and fungi. Studies have confirmed that these bacteria can improve the immune system functions, depression, obesity, etc. They also provide important nutrients to the cells lining the digestive tract. This book contains some path-breaking studies in the field of bioactive foods. It presents researches and studies performed by experts across the globe. As this field is emerging at a rapid pace, the contents of this book will help the readers understand the diferent aspects of probiotics and prebiotics.