Snack Foods and Their Impact on Gastrointestinal Microbiology, Function and Symptoms (OptiGut)

Snack Foods and Their Impact on Gastrointestinal Physiology, Luminal Microbiology and Gastrointestinal Symptoms

The purpose of this study is to evaluate the impact of replacing usual snacks with alternative snack foods on gut health in a population of habitual snackers with low fibre intake.

Study Overview

• Status: Completed
• Conditions: Eating Behavior; Human Microbiome
• Intervention / Treatment: Dietary supplement: Intervention snack 1; Dietary supplement: Intervention snack 2; Dietary supplement: Control snack

Detailed Description

Diet is a crucial target for the improvement of human health. In the modern world, diets are diverse and diet related diseases are becoming more and more common. In particular, it is becoming increasingly apparent that the bacteria that live in the gut are strongly linked to both diet and health. Bacteria in the gut can be beneficial or harmful, and the health of the gut relies on the beneficial bacteria outnumbering the harmful ones. Diet has a great impact on the bacterial composition of the gut. In turn, the gut bacteria play diverse roles in human health, influencing not only the gut but also the health of the immune system, heart and brain. Therefore, optimising the composition of the gut bacterial is vital to human health and wellbeing.

It has been shown that snacks between meals contributes 420 - 480 calories per day, almost a quarter of the recommended intake. Therefore, snack choices are an area of diet and lifestyle that have the potential to influence diet and in turn the health of our gut and gut bacteria. We would like to assess the effect of replacing usual snacks with alternative snack foods that we believe have benefits for gut health.

The primary aim of the study is to investigate whether the replacement of usual snacks has an effect on gut bacterial composition, specifically the abundance of Bifidobacteria. Secondary aims include the effect of the intervention snacks on additional measures of gut health such as gut transit time, the frequency and consistency of bowel movements and gut symptoms e.g. heartburn, nausea, belching etc. The effect of snack foods on metabolites in the blood (e.g. glucose, insulin, lipids) will also be determined. Finally the impact of snack replacement on mood and quality of life will be assessed.

• Study Type: Interventional
• Enrollment (Actual): 87
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • London, United Kingdom, SE1 9NH
    • King's College London Waterloo Campus

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Male or female
• Aged between 18-45 years
• Body mass index (BMI) of 18.5 - 29.9 kg/m2
• Regular consumption of snacks (≥2 per day, excluding fruit and nut snacks)
• Low fibre intake (<22 g/d)
• Willing to follow the protocol and provide consent

Exclusion Criteria:

• Allergy or intolerance to snack ingredients (assessed at screening)
• Dislike of study snacks
• Regular consumption of intervention foods as snacks (twice a day in last month)
• Diabetes
• Major active psychiatric conditions (e.g. schizophrenia) or current eating disorder
• Active treatment for cancer in the last year
• Severe renal, cardiac or pulmonary disease or any other chronic medical condition
• Severe oesophagitis, gastritis or duodenitis
• Active diverticulitis or intestinal/colonic strictures
• Crohns disease or Ulcerative colitis
• Abdominal surgery (except appendicectomy or cholecystectomy)
• Irritable bowel syndrome
• Functional constipation
• Functional diarrhoea
• Antibiotics (past 4 weeks)
• Ongoing therapy with drugs affecting gastrointestinal motility
• Use of medical devices (Pacemakers, infusion pumps, insulin pumps)
• Women who are pregnant/lactating/planning pregnancy
• Recent/ongoing consumption of probiotics/prebiotics (past 4 weeks)
• Ongoing abuse of alcohol/drugs/other medication
• Very high physical activity levels
• Unexplained/unintentional weight loss in the past 6 months

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Intervention snack 1; Snack food believed to selectively promote the growth of beneficial bacterial strains in the human colon.	Dietary supplement: Intervention snack 1; To be eaten instead of regular snacks twice a day for 4 weeks.
Active Comparator: Intervention snack 2; Snack food believed to selectively promote the growth of beneficial bacterial strains in the human colon.	Dietary supplement: Intervention snack 2; To be eaten instead of regular snacks twice a day for 4 weeks.
Placebo Comparator: Control snack; Control snack food reflecting the macro-nutrient profile of a typical UK snack.	Dietary supplement: Control snack; To be eaten instead of regular snacks twice a day for 4 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Faecal bifidobacteria	Measured by 16S community profiling (Illumina Miseq) of bacterial genomic DNA isolated from participant stool samples	Baseline
Faecal bifidobacteria	Measured by 16S community profiling (Illumina Miseq) of bacterial genomic DNA isolated from participant stool samples	Day 28

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Whole gut transit time	Measured using the SmartPill wireless motility capsule	Baseline
Whole gut transit time	Measured using the SmartPill wireless motility capsule	Day 28
Regional gut transit time	Measured using the SmartPill wireless motility capsule	Baseline
Regional gut transit time	Measured using the SmartPill wireless motility capsule	Day 28
Regional gut pH	Measured using the SmartPill wireless motility capsule	Baseline
Regional gut pH	Measured using the SmartPill wireless motility capsule	Day 28
Faecal gut microbiota (alpha- and beta-diversity)	Measured by 16S community profiling (Illumina Miseq) of bacterial genomic DNA isolated from participant stool samples	Baseline
Faecal gut microbiota (alpha- and beta-diversity)	Measured by 16S community profiling (Illumina Miseq) of bacterial genomic DNA isolated from participant stool samples	Day 28
Faecal short-chain fatty acids (SCFA)	Measured by gas liquid chromatography of stool sample	Baseline
Faecal short-chain fatty acids (SCFA)	Measured by gas liquid chromatography of stool sample	Day 28
Faecal water	Measured by lyophilization of stool sample	Baseline
Faecal water	Measured by lyophilization of stool sample	Day 28
Faecal volatile organic compounds	Measured by gas-chromatography mass-spectrometry of stool samples	Baseline
Faecal volatile organic compounds	Measured by gas-chromatography mass-spectrometry of stool samples	Day 28
Gut symptoms	Gastrointestinal symptoms rating scale (7-day; questionnaire)	Week 0
Gut symptoms	Gastrointestinal symptoms rating scale (7-day; questionnaire)	week 4
Stool frequency	Bristol stool form scale (7-day; questionnaire)	Week 0
Stool frequency	Bristol stool form scale(7-day; questionnaire)	Week 4
Dietary intake	7-day food diary	Week 0
Dietary intake	7-day food diary	Week 4
Quality of life	SF-36 questionnaire	Baseline
Quality of life	SF-36 questionnaire	Day 28
Mood	Hospital anxiety and depression scale	Baseline
Mood	Hospital anxiety and depression scale	Day 28
Physical activity	Recent physical activity questionnaire	Baseline
Physical activity	Recent physical activity questionnaire	Day 28
Dietary metabolites (various)	Measured in blood sample	Baseline
Dietary metabolites (various)	Measured in blood sample	Day 28
Particle size of masticated snack foods	Mechanical sieving and laser diffraction of masticated snack foods	Day 28

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Adverse events	Interview-administered questionnaire	From baseline - day 28
Acceptability of snack products	Questionnaire	Day 28

Collaborators and Investigators

• Sponsor: King's College London
• Collaborators: Queen Mary University of London; University of Liverpool
• Investigators: Principal Investigator: Kevin Whelan, Prof., King's College London

Publications and helpful links

General Publications

• Creedon AC, Dimidi E, Hung ES, Rossi M, Probert C, Grassby T, Miguens-Blanco J, Marchesi JR, Scott SM, Berry SE, Whelan K. The impact of almonds and almond processing on gastrointestinal physiology, luminal microbiology, and gastrointestinal symptoms: a randomized controlled trial and mastication study. Am J Clin Nutr. 2022 Dec 19;116(6):1790-1804. doi: 10.1093/ajcn/nqac265.

Study record dates

Study Major Dates

• Study Start (Actual): April 27, 2018
• Primary Completion (Actual): September 30, 2019
• Study Completion (Actual): September 30, 2019

Study Registration Dates

• First Submitted: June 23, 2018
• First Submitted That Met QC Criteria: July 9, 2018
• First Posted (Actual): July 10, 2018

Study Record Updates

• Last Update Posted (Actual): February 5, 2020
• Last Update Submitted That Met QC Criteria: February 3, 2020
• Last Verified: February 1, 2020

More Information

Terms related to this study

• Keywords: Microbiome; Gut Microbiota; Snack; Gut Health
• Other Study ID Numbers: HR-17/18-5341

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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