Impact of Dietary Fibre Consumption on Digestive Comfort

Study Overview
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Brief Summary
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The purpose of this randomised, placebo-controlled, cross-over study is to compare the impact different fibres have on gastrointestinal symptoms when they are consumed individually or as mixtures in healthy adults. The impact of different fibres on the experience of symptoms and stool parameters will be assessed.

Detailed Description
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Global sugar consumption is higher than recommended and there are suggestions that this may be linked to the development of non-communicable diseases including dental caries, and obesity. There are many alternatives to sugars that can be used in foods including certain dietary fibres such as inulin or fructo-oligosaccharides. Most dietary fibres can be fully or partially fermented in the colon by the commensal microbiota, producing beneficial bioactive molecules. However, the rapid production of gas during the fermentation of highly soluble fermentable fibres may cause undesirable symptoms for some people. Dietary exposure to the fibres used in food reformulation, including inulin and soluble corn fibre, is increasing and the impact this may have on gastrointestinal symptoms is unclear. The impact of fibres with different physicochemical characteristics and fermentabilities may differ when consumed in mixtures compared to individually. The aim of this study is to investigate the impact different fibres have on gastrointestinal symptoms when they are consumed individually or as mixtures and how this relates to the composition of the stool.

Official Title
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Impact of Dietary Fibre Consumption on Digestive Comfort

Conditions
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Gastrointestinal Discomfort

Intervention / Treatment
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* Dietary Supplement: Soluble corn fibre
* Dietary Supplement: Inulin
* Dietary Supplement: soluble corn fibre and inulin
* Dietary Supplement: Maltodextrin


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: Self-reported healthy adults (aged 18-65y) Non-smokers Exclusion criteria: Individuals with any allergies or conditions affecting bowel health e.g. inflammatory bowel disease (Crohn's disease or ulcerative colitis), irritable bowel syndrome, coeliac disease or diverticular disease Individuals who are pregnant or are trying to get pregnant Individuals with any food allergies Individuals who have taken antibiotics in the past 3 months Individuals who regularly take medication that may modify gastrointestinal function e.g. prokinetic agents (e.g. metoclopramide), antiemetics, constipation treatments (e.g. lactulose, polyethylene glycol) Individuals who consume ≥25g fibre per day

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Healthy adults will be recruited for this single blind randomised controlled cross over study. Participants will be provided with powdered fibres and a non-fibre control (blinded) with detailed instruction on how to dilute these to produce an orange flavoured drinks. They will record any digestive symptoms experienced over four different 7-day intervention arms. The participants will record their bowel habits (stool frequency and form) during these intervention periods and provide stool samples before and after each period from which we will measure pH, water content and short chain fatty acids (SCFA) concentration.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Soluble Corn fibre<br>Soluble corn fibre (SCF) (15g fibre/day) | Dietary Supplement: Soluble corn fibre<br>* As a powdered beverage<br>|
| Experimental: Inulin<br>Inulin (In) (15g fibre/day) | Dietary Supplement: Inulin<br>* As a powdered beverage<br>|
| Experimental: Soluble corn fibre and inulin<br>SCF + In (15g/day fibre) | Dietary Supplement: soluble corn fibre and inulin<br>* As a powdered beverage<br>|
| Placebo Comparator: Control (Maltodextrin)<br>Control (Maltodextrin) (0g fibre) | Dietary Supplement: Maltodextrin<br>* As a powdered beverage<br>* Other names: Placebo;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Symptom frequency and intensity scores | Symptom frequency and intensity scores for abdominal pain, abdominal bloating and flatulence individually will be reported during each 7-day feeding period. Symptoms will be analysed individually and in combination to create a composite score using a visual analogue scale. This entails making a mark on a horizontal line of 10cm indicating 0 (no symptom) to 10 (worst imaginable symptom). Participants will record the occurrence of each symptom and rate the severity using this scale. The combined score is the sum of each of the symptoms. | over 7 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Stool frequency | Diary | over 7 days | 
| Stool form using the Bristol stool chart | Diary for each event | Over 7 days | 
| Stool water content | 2 samples each week | Day 1 and day 7 | 
| Stool acidity | 2 samples each week | Day 1 and day 7 | 
| Stool SCFA concentrations | 2 samples each week | Day 1 and day 7 |