The Effect of Micronutrient Supplementation on Gut Microbiome Composition and Function

Study Overview
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Brief Summary
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The main aim of this randomized crossover study is to explore the effect of micronutrient supplementation on gut microbiota composition and function in healthy volunteers. Participants will undertake two 10-day trials with a replicated diet separated by a 15-day washout period. For one of these trials, participants will take a daily over-the-counter multivitamin supplement. Faecal and urine samples will be collected at the start and end of each trial to assess changes in gut microbiota composition, urinary and faecal metabolomics, and targeted bacterial metabolites including short chain fatty acids, sulphide, and lactate.

Detailed Description
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Exploring the effect of habitual dietary patterns on human gut microbiota and on host health is an area of scientific interest and a major funding theme in UKRI. The main aim of this proof-of-concept study is to explore the effect of micronutrient supplementation on gut microbiota composition and function in healthy volunteers. Participants will be asked to undertake two trials with 15 day washout in-between. If the participants are allocated to the supplementation group they will be asked to consume an over-the-counter multivitamin supplement for 10 days (1 tablet per day) in addition to their usual diet. Participants will provide faecal and urinary samples prior to initiation of the intervention and again at the end of the 10-day supplementation. During these 10 days participants will be asked to record the meals they consume on provided food diaries. If the participants are allocated to the control group, participants will be asked to provide the same number of samples and at the same intervals as the supplementation group (i.e. at baseline and after 10 days) but without receiving micronutrient supplementation. Participants will also be asked to replicate as close as possible the diet they had followed during the first trial they were allocated. Between the two trials, participants will follow a wash-out period of 15 days with the aim of reverting the gut microbiota characteristics back to baseline levels. The main outcome measures of this study are to assess changes in gut microbiota composition based on 16S rRNA gene amplicon sequencing, changes in urinary/faecal metabolomics, and changes in targeted bacterial metabolites (short chain fatty acids, sulphide, lactate).

Official Title
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The Effect of Micronutrient Supplementation on Gut Microbiome Composition and Function

Conditions
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Gastrointestinal Microbiome

Intervention / Treatment
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* Dietary Supplement: Multivitamin Supplementation
* Other: Dietary Replication


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy adults >18 y Exclusion Criteria: History of previous major gut surgery, Unstable weight, Use of pre/probiotics, micronutrient supplements, antibiotics, or steroids the last 3 months Participation in other research

Ages Eligible for Study
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Minimum Age: 18 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
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Supplementation<br>In this arm of the study, participants will take 1 multivitamin pill each day for 10 days. If this is the participant's first trial, they will also record their diet in a 10-day estimated food diary. If this is the participant's second trial, they will replicate their diet recorded from their first trial. | Dietary Supplement: Multivitamin Supplementation<br>* Participants will supplement daily with an over-the-counter oral multivitamin pill<br>Other: Dietary Replication<br>* Patients will record their dietary intake in an estimated food diary during the first trial. During the second trial, participants will be asked to replicate their diet from the first trial<br>|
| Other: Control<br>In this arm of the study, participants will not supplement with any multivitamin. If this is the participant's first trial, they will record their diet in a 10-day estimated food diary. If this is the participant's second trial, they will replicate the diet recorded from their first trial. | Other: Dietary Replication<br>* Patients will record their dietary intake in an estimated food diary during the first trial. During the second trial, participants will be asked to replicate their diet from the first trial<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in gut microbiota composition during multivitamin supplementation | Changes will be assessed via 16S rRNA gene amplicon sequencing from DNA extracts of faecal samples | This will be assessed 4 times throughout the study. This will be assessed at the beginning (day 0) and end (day 10) of each 10-day trial. | 
| Changes in concentrations of faecal and urinary metabolites during multivitamin supplementation | Concentration of several urinary and faecal metabolites will be assessed via 1H NMR spectroscopy in urine and faecal samples from study participants. Changes during multivitamin supplementation will be investigated. | This will be assessed 4 times throughout the study. This will be assessed at the beginning (day 0) and end (day 10) of each 10-day trial. | 
| Changes in bacterial metabolites during multivitamin supplementation | Changes in targeted bacterial metabolites including short chain fatty acids, sulphide, ammonia, lactate, succinate, ethanol | This will be assessed 4 times throughout the study. This will be assessed at the beginning (day 0) and end (day 10) of each 10-day trial. |