A randomised, placebo-controlled cross-over study of the effect of chronic feeding of methylcellulose and inulin on inulin fermentation in people with IBS-C
Irritable bowel syndrome
Interventions: study participants will be given two food interventions in a randomised order: 1. A firm gel containing inulin and methylcellulose 2. A liquid containing inulin and maltodextrin (placebo). They will be prepared in the food production facility at the University of Nottingham and stored in the fridge at 4°C and then in the participants’ fridges. All interventions will be prepared to the same concentration of inulin and intervention (methylcellulose) or placebo (maltodextrin), which is based on a volume of 375 ml water with either; 1. 15 g inulin + 15 g methylcellulose in a pot providing a final firm texture after heating 2. 15 g inulin + 15 g maltodextrin in a pot for a final drinkable texture This is a single-centre, two-way, cross-over study in people with IBS and constipation who will receive either inulin plus maltodextrin (placebo) or inulin plus methylcellulose both given at a dose of 5 g three times daily for 3 weeks. MRI assessment will be performed using a 3 Tesla (3T) whole-body MRI system (Philips Achieva) scanner of mechanistic endpoints at baseline and after 3 weeks of the intervention. The two studies are to be separated by a 4-week washout period.
Meet Rome IV criteria for IBS with constipation
1. Pregnancy, lactating, or planning pregnancy during the course of the investigation declared by the candidate 2. History declared by the candidate of pre-existing gastrointestinal disorder other than IBS-C that may affect bowel function including but not limited to: 3. Inflammatory Bowel Disease 4. Coeliac Disease 5. Pancreatitis 6. Gallstone disease (biliary colic, cholecystitis; asymptomatic presence of gallstones permitted) 7. Complicated diverticulitis (asymptomatic presence of diverticula permitted) 8. Cancer of the gastrointestinal tract 9. Gastroparesis 10. Other functional gastrointestinal disorders will be permitted as they frequently co-exist with IBS. 11. Reported history of previous resection of the oesophagus, stomach, or intestine (excluding appendix) 12. Intestinal stoma 13. Have contraindications for MRI scanning i.e. metallic implants, pacemakers, history of metallic foreign body in eye(s) and penetrating eye injury 14. Unable to lie flat and relatively still for less than 5 minutes 15. Any medical condition potentially compromising participation in the study e.g., diabetes mellitus, respiratory disease limiting ability to use breath hydrogen analyser, known intolerance to one of the test substances 16. Has a body mass index (BMI) value less than 18.5 or greater than 35 17. Will not agree to follow dietary and lifestyle restrictions required 18. Unable to stop opiate use or planning to change medication which might alter GI motility. 19. Mebeverine, calcium channel antagonists, selective serotonin reuptake inhibitors, low-dose tricyclic antidepressants, antihistamines, and oral contraceptive pills will be recorded in the CRF but will not be an exclusion criteria provided no change in dosage is planned during the study period. 20. Participants who have taken antibiotics or probiotics within the last 4 weeks 21. Poor understanding of the English language 22. Participation in night shift work the week prior to the study day.