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Exploring Mechanism of Action of Dietary Fibre on the Gut Microbiota and Metabolites

NCT05906589 · Status: COMPLETED · Phase: NA · Type: INTERVENTIONAL · Enrollment: 40

Last updated 2026-02-12

No results posted yet for this study

Summary

Cancer patients receiving pelvic radiotherapy suffer side effects to the intestine, including diarrhoea and occasionally rectal bleeding, often worsened by chemoradiation. Many pelvic radiotherapy patients receive a form of dietary fibre, psyllium husk, to manage their diarrhoeal symptoms. There is evidence in mice that dietary fibre supplementation can improve tumour response and reduce normal tissue side effects caused by radiation. If this were to be confirmed in humans, it would be a major advance in patient treatment. The investigators will conduct a study in healthy subjects to assess mechanisms and response to dietary fibre.

The investigators will conduct a within-subject diet intervention study on healthy older adults (\>60 years old) to determine if a subset of the population are responders to dietary fibre manipulation, using inulin with or without psyllium. This will allow assessment of the physiological impact of dietary fibre. Participants will receive placebo, inulin, or psyllium plus inulin in random order (6 possible combinations) for two weeks each with two-week washout periods.

Baseline faecal microbial activity, short chain fatty acid (SCFA) concentrations, and habitual fibre intake, determined by dietary questionnaires/food diaries will be used to identify individuals in whom dietary fibre manipulation might have a positive impact. Individuals who respond to dietary fibre supplementation may be found to have elevated levels of some SCFAs and significantly increased relative abundance of certain microbiota. Dietary parameters, bacterial relative abundance and SCFA levels will be correlated with plasma cytokine levels.

Conditions

  • Psyllium
  • Inulin

Interventions

DIETARY_SUPPLEMENT

Inulin

The participant will take inulin twice daily over a 14 day period.

DIETARY_SUPPLEMENT

Psyllium

The participant will take psyllium twice daily over a 14 day period.

DIETARY_SUPPLEMENT

Maltodextrin

The participant will take maltodextrin twice daily over a 14 day period.

Sponsors & Collaborators

  • University of Aberdeen

    lead OTHER

Principal Investigators

  • Anne E Kiltie, Prof · University of Aberdeen

Study Design

Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
DOUBLE
Model
CROSSOVER

Eligibility

Min Age
60 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2023-09-07
Primary Completion
2025-07-10
Completion
2025-07-10

Countries

  • United Kingdom

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT05906589 on ClinicalTrials.gov