Problem being addressed:
IBS is a complex syndrome without a known cause or clear diagnostic markers, although it has often been linked to issues with diet or digestive transit time. Recently, research has focussed in particular on the role of the microbiome, which is thought to be altered in many IBS patients, leading to altered carbohydrate ultilisation. As a result, many clinical guidelines suggest IBS sufferers avoid the consumption of a common form of fermentable carbohydrate, resistant starch (RS). There is not, however, a mechanistic basis to understand the difference in RS fermentation between healthy individuals and IBS suffers. This project aimed to address this through identifying mechanistic differences in RS fermentation between healthy and IBS patient microbiota.
Why is it important for society:
IBS is a major societal problem, as one of the most widely diagnosed disorders in Europe. Although not fatal, the associated deterioration in quality of life and co-morbidities pose major challenges for health care systems. There is currently no known cure for IBS, and the economic and healthcare costs are highly significant, as well as the impact on quality of life for individual sufferers. Current interventions for IBS are primarily diet based, for example the commonly used FODMAP diet, which aims to restrict fermentable carbohydrate intake. This diet, although successful in helping many IBS sufferers, is highly restrictive and the long-term health effects of removing fermentable carbohydrates from the diet are unclear. Therefore, there is a pressing societal need for improved dietary interventions in IBS, which can be informed by a better mechanistic understanding of the fermentation of different carbohydrates by the IBS microbiota.
Overall objectives:
The overall objectives of this project are:
1. Selecting a range of RS from the same botanical origin, but with different structural processing resulting in different mechanisms of resistance to digestion
2. Obtaining healthy and IBS patient faecal inoculum, including ethical approval for the study, and using these samples to seed ex vivo model colon systems containing contrasting RS substrates and analysing the kinetics of gas production during fermentation of the RS substrates.
3. Carrying out metabolomic and next generation 16S sequencing analysis on samples of media taken from fermentation vessels during the time course of fermentation of different RS substrates with healthy or IBS faecal inoculum to identify differences in microbial community composition and carbohydrate metabolism.
