Introduction -- Chapter 1: The Importance of the Microbiome in the Gut -- Chapter 2: The Players within the Intestinal Microbiome -- Chapter 3: The Role of Enteric Infection and the Microbiome in Human Health and Disease -- Chapter 4: Gut Microbes - The Gut-Brain Connection -- Chapter 5: Changes in the Gut Microbiome as seen in Diabetes and Obesity -- Chapter 6: The Role of Gut Bacteria in Functional Gastrointestinal Disorders -- Chapter 7: How the Microbiome Affects the Risk for Colon Cancer -- Chapter 8: The Role of the Microbiome in Inflammatory Bowel Disease -- Chapter 9: Fecal Transplant: The Benefits and Harms of Fecal Microbiota Transplantation -- Chapter 10: Future Directions.