The gut microbiome is important in the homeostasis of gut health and has pivotal roles in digestion, immune regulation, and metabolic processes. The gut microbiome has been implicated in range of diseases and there is a rapidly growing understanding of this ecosystem’s importance in inflammatory bowel disease. We have yet to identify a single microbe that causes either ulcerative colitis or pouchitis, however, perturbations in the gut microbiome are associated with disease states. Importantly, we can manipulate the gut microbiome using dietary interventions, medications, and faecal microbiota transplantation. This review will summarise our knowledge of gut microbiome therapies in ulcerative colitis and pouchitis.