In a normal physiological state, several bacteria are present in the human gut that is essential to maintain the normal to healthy gastrointestinal function. Disturbances in this “normal flora” lead to gut inflammation and infection. This volume explores the potential of probiotics, the healthy bacteria, to manage gut-related diseases including gastrointestinal cancers, ulcerative colitis, H. pylori infections, and diarrhea; vaginosis; oral health; airway inflammation; and atopic dermatitis. The concept of designer probiotics, edible vaccines and future scope of research in the field is also presented. The animal models used for studying the benefits of probiotics in gut inflammation are described for beginners.