Clinical trial NCT06580132: The Effects of Dietary Fibres on Metabolic Health and the Gut Microbiome
Official title: The Modulatory Effects of Dietary Fibres on the Composition and Function of the Gut Microbiome- A Pilot Randomised Placebo-controlled Dietary Intervention Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Diet
Healthy
Systemic Inflammatory Response
Keywords: Dietary intervention
Gut microbiome
Systemic inflammation
Lead sponsor: University of Nottingham
Sponsor class: OTHER
First posted: 2024-08-30
Enrollment: 19
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Controlled intervention
Primary purpose: BASIC_SCIENCE

Brief summary: 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 (the current trial focussed on pectin) 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. In the week before each study visit, participants will record their food intake.

Detailed description: The overall aim of the proposed project is to unlock the effect of dietary fibres (i.e. LM Pectin) 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 dietary 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 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 be asked to complete some questionnaires. After completion of the first study day, participants will be randomised to receive either the dietary fibre 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.

Eligibility criteria: 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:

The participant may not enter the study if ANY of the following apply:

* 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/ taking prebiotic supplements
* Pregnant or breastfeeding
* 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.

Primary outcomes:
measure: Change in microbiome profile
timeFrame: 4 weeks
measure: Change in inflammatory profile
timeFrame: 4 weeks
measure: Changes in short chain fatty acids (SCFAs)
timeFrame: 4 weeks
Secondary outcomes:
measure: Change in systolic blood pressure (lying to standing) pre intervention
timeFrame: 4 minutes
measure: Change in systolic blood pressure (lying to standing) post intervention
timeFrame: 4 minutes
measure: Change in diastolic blood pressure (lying to standing) pre intervention
timeFrame: 4 minutes
measure: Change in diastolic blood pressure (lying to standing) post intervention
timeFrame: 4 minutes
measure: Change in Short Form Health Survey (SF12) Questionnaire aggregated normalised 'physical' score
timeFrame: 4 weeks
measure: Change in Short Form Health Survey (SF12) Questionnaire aggregated normalised 'mental' score
timeFrame: 4 weeks
measure: Change in Pittsburgh Sleep Quality Index (PSQI)
timeFrame: 4 weeks
measure: Change in Hospital Anxiety and Depression Score (HADS)
timeFrame: 4 weeks
Other outcomes:
Locations:
city: Nottingham
country: United Kingdom
facility: University of Nottingham
Study officials:
affiliation: University of Nottingham
name: Ana Valdes, Professor
role: PRINCIPAL_INVESTIGATOR
References: