Resistant Starch and Non-starch Polysaccharide (Dietary Fibre) Intake and the Colonic Microbiome in Older People

Study Overview
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Brief Summary
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The development of preventative nutritional strategies to promote healthy ageing is becoming increasingly important. Elevated thresholds for taste and smell, coupled with swallowing difficulties and masticatory dysfunction, often result in nutritionally imbalanced diets among the elderly. This can induce great changes in the composition and metabolic activities of the gut microbiome, leading to decreased intestinal motility and impaired bowel function. This can result in constipation or diarrhoea, increased basal levels of inflammation, immunosenescence and morbidity. The objectives of this study are to use dietary modification to improve gut health in older people. Diets high in resistant starch or dietary fibre will be given to 50 elderly volunteers (70-95 years) living in the community, in a randomised double-blind cross-over study. The aim is to investigate the effects on microbiome composition and functionality through fermentation, reduced putrefaction, and modification of blood markers associated with obesity and diabetes.

Official Title
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Resistant Starch and Non-starch Polysaccharide (Dietary Fibre) Intake in Relation to the Structure and Metabolic Activities of the Colonic Microbiome in Older People

Conditions
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Aging

Intervention / Treatment
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* Dietary Supplement: Resistant starch
* Dietary Supplement: Dietary fibre (arabinogalactan, gum guar, pectin)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Men and women aged 70-95 years, with BMI 18.5-30.0 kg m2. Exclusion Criteria: Exclusion criteria will include asplenia and other acquired or congenital immunodeficiencies Any autoimmune disease Self-reported symptoms of acute or recent infection (including use of antibiotics within the previous 3 months) Taking probiotics or prebiotics, including lactulose for constipation Chronic gastrointestinal problems (e.g. Inflammatory Bowel Disease, Irritable Bowel Syndrome, cancer). Specifically, volunteers who are diabetic will not be excluded from the investigation. Assessment will be on a case by case basis.

Ages Eligible for Study
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Minimum Age: 70 Years
Maximum Age: 95 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: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Resistant starch (RS)<br>Resistant starch (RS3) | Dietary Supplement: Resistant starch<br> <br> |
| Experimental: Dietary fibre<br>Dietary fibre (Arabinogalactan, gum guar, pectin) | Dietary Supplement: Dietary fibre (arabinogalactan, gum guar, pectin)<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of participants with change in levels of faecal bifidobacteria measured by quantitative fluorescent in situ hybridisation (FISH). |  | 4 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of participants with change in the bacterial composition of the faecal microbiome measured by quantitative FISH. |  | 4 weeks | 
| Number of participants with change in inflammatory markers linked to ageing measured in whole blood by enzyme linked immunosorbent assay (ELISA). | Measurement of cytokines Interleukin 6 (IL-6), Tumour necrosis factor-alpha (TNF-alpha), IL-1, IL-10, Interferon-gamma (INF-gamma), IL-4, IL-8, Monocyte chemoattractant protein 1( MCP-1) and serum C-reactive protein (CRP). | 4 weeks | 
| Number of participants with change in faecal genotoxic potential determined by measurement of faecal bacterial enzymes involved in the formation of genotoxic metabolites in the gut. | Enzymes to be measured beta-glucosidase, beta-glucuronidase, azoreductase, nitroreductase | 4 weeks | 
| Number of participants with a change in bowel habit and quality of life measured by completion of a bowel habit diary and quality of life questionnaire. |  | 4 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Aging, Resistant starch, Dietary fibre, Immune system, Bacteria, older subjects