Some carbohydrates (complex sugars) which are found in grains, fruit and vegetables, cannot be digested by humans. When eaten they pass through the small bowel to the large bowel, or colon. Some bacteria that live in the colon are able to digest these carbohydrates, and use them as an energy source. This releases energy that humans can absorb, and may have other effects on health as well. The process also releases gases such as hydrogen and methane into the colon, which will eventually be released as flatulence.

There is some evidence in animals, and humans, that changing the carbohydrate content of the diet may increase the numbers of bacteria in the colon that can use this energy source. Recent work has looked at how changes in colon bacteria and carbohydrate in the diet affect transit, the speed at which food and stool moves through the stomach and bowels. This undergraduate project will use techniques in Magnetic Resonance Imaging developed in Nottingham to investigate how a prolonged change in dietary carbohydrate might affect speed of transit through the bowel and gas production in the colon, and whether there is any evidence of a change in the level of signalling chemicals that may affect bowel function.

Inclusion Criteria:

• Aged 18-55
• Able to give informed consent
• Does not meet criteria for diagnosis of IBS on Rome III questionnaire

Exclusion Criteria:

• Unable to abstain from smoking for the duration of the study (may affect breath hydrogen readings)
• Self-declared vegetarian, vegan or kosher/ halal diet who cannot eat carmine red dye
• Pregnancy declared by candidate
• Female patients during their menstrual period
• History declared by the candidate of pre-existing gastrointestinal disorder, including but not limited to:
• Inflammatory Bowel Disease
• Coeliac Disease
• Pancreatitis
• Gallstone disease (biliary colic, cholecystitis)
• Diverticulitis
• Cancer of the gastrointestinal tract
• Irritable Bowel Syndrome
• Reported history of previous resection of any part of the gastrointestinal tract other than appendix or gallbladder
• Intestinal stoma
• Any medical condition making participation potentially compromising participation in the study e.g. diabetes mellitus, respiratory disease limiting ability to lie in the scanner
• Contraindications for MRI scanning i.e. metallic implants, pacemakers, history of metallic foreign body in eye(s) and penetrating eye injury
• Reported alcohol dependence
• Unable to stop drugs known to alter GI motility including mebeverine, opiates, monoamine oxidase inhibitors, phenothiazines, benzodiazepines, calcium channel antagonists during or in the 2 weeks prior to the test. (Selective serotonin reuptake inhibitors and low dose tricyclic antidepressants will be recorded but will not be an exclusion criteria)
• Antibiotic or probiotic treatment in the past 4 weeks
• Inability to lie flat or exceed scanner limits of weight <120kg
• Poor understanding of English language
• Participation in night shift work the week prior to the study day. Night work is defined as working between midnight and 6.00 AM
• Strenuous exercise greater than 10 hours per week (i.e. no competition training the week prior to the study).
• Participation in any medical trials for the past 3 months
• Anyone who in the opinion of the investigator is unlikely to be able to comply with the protocol e.g. cognitive dysfunction, chaotic lifestyle related to substance abuse