Effect of Chronic Feeding of Inulin And Methylcellulose on Colonic Fermentation

Overview

To determine the effect on tolerance and gas production from chronic feeding of fermentable fibre (inulin) incorporated into a gel forming fibre (methylcellulose) compared with placebo (maltodextrin)

Our challenge is to understand how various dietary fibres interact to alter colonic fermentation of FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) with the aim of reducing gaseous distension of the colon and hence symptoms. Our previous studies have shown how psyllium, a gel forming natural fibre can reduce gas production induced by a dietary FODMAP inulin when it reaches the colon. The investigators are exploiting a range of food grade modified celluloses which can form gels at body temperature to perform human studies to explore whether the beneficial effect of psyllium is unique or will be found with all gelling substances 2. The investigators have completed a study using a modified methylcellulose which was shown to be non-inferior to psyllium. Our previous studies point to the importance of habitual FODMAP intake which is likely to alter the microbiota, selecting those that can efficiently utilise fructans. The investigators want to understand whether chronic feeding of inulin along with methylcellulose, a gel-forming dietary fibre which persists in the colon, will significantly alter the tolerance to inulin relative to chronic feeding of inulin with a suitable placebo maltodextrin. Maltodextrin is rapidly absorbed in the small bowel and therefore has no effect on colonic fermentation. The investigators plan to run a chronic feeding study in IBS patients and wish to ascertain tolerability of repeated use as previous studies have only provided single doses. With this in mind, the investigators plan to provide inulin and methylcellulose for daily consumption by healthy adults for a period of two weeks. The intervention will be divided into 3 portions to be taken before breakfast, lunch and supper. In week 1, the portions will contain 2.5 g of both inulin and methylcellulose in 62.5 mL water. In week 2, the portions will contain 5.0 g of both inulin and methylcellulose in 125 mL water. The participants will also follow the same chronic feeding schedule but with a maltodextrin placebo as opposed to methylcellulose, with randomisation of study schedule taking place at screening. The investigators will use MRI at baseline and at 2 weeks to assess changes in colonic volume and transit utilising high MRI contrast capsules54. The investigators will collect stool samples at baseline and after 1 and 2 weeks of chronic feeding for each study intervention to monitor the expected changes in microbiota. The primary objective is to assess the fermentation of inulin given as a single 15g with or without methylcellulose from the breath hydrogen response at baseline and after the 2 weeks feeding. .

Conditions

Interventions

Eligibility

Locations (2)

Outcomes

Central Contacts