Effect of Pectin and Inulin Fibre Supplementation on Glucose and ANS Modulation

The Role of Dietary Fibres in Modulating Blood Glucose and the Autonomic Nervous System - A Pilot Randomised Placebo-controlled Dietary Intervention Study

The study involves intake of dietary supplements, which are commonly found in the UK diet (not pharmacological agents) to test their effects on inflammation in the body and gut microbiome composition. Study subjects will be healthy volunteers recruited from the University and local population and will be asked to attend the laboratory on 2 occasions; before and after 4-week' supplementing the diet daily with either the dietary fibres (Pectin and Inulin) or placebo (maltodextrin). At each study visit (~3hrs), participants will be asked to provide a stool and blood sample and will have blood pressure measured. They will also consume a glucose drink to assess how effectively the body regulates its blood glucose concentration. In the week before each study visit, participants will wear an activity and glucose monitor and record their food intake.

Study Overview

• Status: Completed
• Conditions: Diet, Healthy; Systemic Inflammatory Response
• Intervention / Treatment: Dietary supplement: Fibre intervention; Dietary supplement: Placebo intervention

Detailed Description

The overall aim of the proposed project is to unlock the effect of two structurally different dietary fibres on anti-inflammatory and cardioprotective metabolic responses via the modulation of the gut microbiome and SCFAs production.

Specific Aim 1: To deliver a wealth of molecular data, including effect sizes, on the physiological effects of two distinct fibres on the changes in the composition and function of the gut microbiome and changes in the metabolomic and physiological profile of an individual.

Specific Aim 2: To investigate the mechanisms whereby the gut microbiome modulates crucial physiological parameters such, blood glucose regulation, hunger and appetite, immune function markers in response to the anti-inflammatory effects of the gut microbiome.

30 healthy, non obese volunteers will be recruited following a successful medical screening. Between recruitment and first study visit, and in the final week of the 4-week intervention (before the second study visit), participants will be asked to wear a wrist-worn activity monitor and a subcutaneous glucose monitor (Freestyle Libre 2; 7 days), to complete a dietary record (4 days), to collect a stool sample on the day before the study visit and to fast from midnight the night before this visit.

At both study visits, participants will have weight, hip/waist circumference and blood pressure measured. They will consume 75g of glucose in 300ml of water (as an oral glucose challenge) and glucose concentration will be monitored over 2 hours via the subcutaneous monitor. They will also be asked to complete some questionnaires. After completion of the first study day, participants will be randomised to receive either the dietary fibres or placebo powder. They will be given the blinded products portioned in individual sachets, with instructions to add the contents of one sachet a day to juice, smoothies or water and to consume immediately. Study visit 2 will be scheduled at the end of the 4 week 'dosing' period.

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Nottingham, United Kingdom, NG7 2UH
    • University of Nottingham

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Participant is willing and able to give informed consent for participation in the study
• Participant eligibility includes those aged >18 years who have a body mass index (BMI) between 18.5 and 39.9 kg/m2

Exclusion Criteria:

• Have psychosocial or gastrointestinal (e.g. malabsorptive conditions such as IBS/IBD, coeliac)
• Are taking the following medications: immunosuppressants, amiodarone and/or perhexiline
• Are currently following or anticipated to commence a specialised commercially available weight loss diet and/or program
• Pregnant or breast feeding
• History or current psychiatric illness
• History or current neurological condition (e.g. epilepsy)
• Having taken part in a research study in the last 3 months involving invasive procedures or an inconvenience allowance (this must remain for ALL UoN FMHS UREC approved studies)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Fibre arm; 15g of pectin and 5g Inulin provided to healthy participants for 4 weeks.	Dietary supplement: Fibre intervention; Inulin fibre (5g) and Pectin fibre (15g) was randomly allocated to eligible participants in order to test specific effects on gut microbiome composition and metabolic markers.
Placebo Comparator: Maltodextrin; 10g of maltodextrin provided as the control to participants for 4 weeks.	Dietary supplement: Placebo intervention; Maltodextrin (10g) served as a control/ placebo to compare the effects observed with inulin and pectin.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in microbiome profile	Change in microbiome profile, assessed using 16s RNA sequencing analysis of faecal samples provided pre and post the 4-week intervention period	4 weeks
Change in inflammatory profile	Change in circulating markers of inflammation measured by ELISAs in serum samples collected pre and post the 4-week intervention period.	4 weeks
Changes in short chain fatty acids (SCFAs)	Change in serum SCFAs measured by mass spectrometry pre and post the 4-week intervention period	4 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in heart rate variability	change in mean heart rate variability, measured across 7 days using a wrist worn activity monitor, before and in the final week of the 4-week intervention	4-weeks
Change in physical activity level (PAL)	change in mean PAL, measured across 7 days using a wrist worn activity monitor, before and in the final week of the 4-week intervention	4-weeks
Change in step count	change in mean step count, measured across 7 days using a wrist worn activity monitor, before and in the final week of the 4-week intervention	4-weeks
Change in systolic blood pressure (lying to standing) pre intervention	Change in systolic blood pressure (measured after 3 minutes of lying down and after 1 minute of standing), at pre-intervention study visit	4 minutes
Change in systolic blood pressure (lying to standing) post intervention	Change in systolic blood pressure (measured after 3 minutes of lying down and after 1 minute of standing), at post-intervention study visit	4 minutes
Change in diastolic blood pressure (lying to standing) pre-intervention	Change in diastolic blood pressure (measured after 3 minutes of lying down and after 1 minute of standing), at pre-intervention study visit	4 minutes
Change in diastolic blood pressure (lying to standing) post-intervention	Change in diastolic blood pressure (measured after 3 minutes of lying down and after 1 minute of standing), at post-intervention study visit	4 minutes
Change in heart rate (lying to standing) pre-intervention	Change in heart rate (measured after 3 minutes of lying down and after 1 minute of standing), at pre-intervention study visit	4 minutes
Change in heart rate (lying to standing) post-intervention	Change in heart rate (measured after 3 minutes of lying down and after 1 minute of standing), at post-intervention study visit	4 minutes
Change in Short Form Health Survey (SF36) Questionnaire aggregated normalised 'physical' score	Change in 'SF36' Questionnaire aggregated 'physical' score (normalised to UK population) calculated according to standard procedures (min 0, max 100), with higher score indicating better physical wellbeing; measured pre and post intervention	4 weeks
Change in Short Form Health Survey (SF36) Questionnaire aggregated normalised 'mental' score	Change in 'SF36' Questionnaire aggregated 'mental' score (normalised to UK population) calculated according to standard procedures (min 0, max 100), with higher score indicating better mental wellbeing; measured pre and post intervention	4 weeks
Change in Pittsburgh Sleep Quality Index (PSQI)	Change in PSQI score (min score 0, max 21), measured pre and post the 4-week intervention, with higher score indicating poorer sleep quality	4 weeks

Collaborators and Investigators

• Sponsor: Elizabeth Simpson
• Investigators: Principal Investigator: Ana Valdes, PhD, University of Nottingham

Study record dates

Study Major Dates

• Study Start (Actual): September 22, 2021
• Primary Completion (Actual): August 28, 2024
• Study Completion (Actual): December 31, 2024

Study Registration Dates

• First Submitted: June 24, 2024
• First Submitted That Met QC Criteria: June 24, 2024
• First Posted (Actual): June 28, 2024

Study Record Updates

• Last Update Posted (Actual): March 28, 2025
• Last Update Submitted That Met QC Criteria: March 24, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Keywords: Systemic inflammation; Gut microbiome; Dietary intervention
• Other Study ID Numbers: FMHS 287-0523

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Data arising from the current study will be used in a fully anonymised format for the purpose of publications.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No