The QIB Colon Model

Inclusion Criteria: * Live or work within 10 miles of the Norwich Research Park. * Having a normal bowel habit; assessed as regular defecation between 3 times a day and 3 times a week, with a form similar to 3-5 on the Bristol Stool Chart. * Do not have any diagnosed chronic gastrointestinal health problem, such as irritable bowel syndrome, inflammatory bowel disease, or coeliac disease. Exclusion Criteria: This will depend on individual experiments but in most cases samples will not be collected from individuals: * who have used antibiotics or probiotics in the last 2 months. * who are pregnant or breast feeding. * who have recently used other medications or food supplements (considered on a study-specific basis). * who have recently had an operation requiring general anaesthetic. * who have had a gastrointestinal upset, such as vomiting or diarrhoea within the last 72hrs.