In order to understand common conditions such as coeliac disease and Crohn's disease, one must view the gut in its evolutionary context. This is the novel approach to the gut and its diseases that is adopted in this book. The first part tells the story of the evolution of the gut itself - why it came about and how it has influenced the evolution of animals ever since. The second part focuses on the evolution of immunity and how the layers of immune mechanisms are retained in the gut, resembling the strata revealed in an archeological dig. The final part, 'The Gastro-Archeologist', ties the first two together and highlights how understanding the gut and immune system in their evolutionary context can help us understand diseases affecting them. Ambitious in its scope but telling a unique story from a refreshingly novel perspective, the book offers an informative and enjoyable read. As the story of the gut, immunity and disease unfolds, the author aims to endow readers with the same sense of awe and excitement that the subject evokes in him. Difficult concepts are illustrated using simple and colourful analogies, and the main content is supplemented with anecdotes and unusual and amusing facts throughout the book. The book is intended for anyone with an interest in the gut, its immunity and diseases, ranging from school and college biology and biomedical students, to professionals working in the field, and to patients suffering from intestinal diseases who want to understand more about their conditions.