Snack Foods and Their Impact on Gastrointestinal Microbiology, Function and Symptoms
- Conditions
- Human MicrobiomeEating Behavior
- Interventions
- Dietary Supplement: Control snackDietary Supplement: Intervention snack 1Dietary Supplement: Intervention snack 2
- Registration Number
- NCT03581812
- Lead Sponsor
- King's College London
- Brief Summary
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.
- 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.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 87
- 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
- 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 & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Control snack Control snack Control snack food reflecting the macro-nutrient profile of a typical UK snack. Intervention snack 1 Intervention snack 1 Snack food believed to selectively promote the growth of beneficial bacterial strains in the human colon. Intervention snack 2 Intervention snack 2 Snack food believed to selectively promote the growth of beneficial bacterial strains in the human colon.
- Primary Outcome Measures
Name Time Method Faecal bifidobacteria Day 28 Measured by 16S community profiling (Illumina Miseq) of bacterial genomic DNA isolated from participant stool samples
- Secondary Outcome Measures
Name Time Method Regional gut transit time Day 28 Measured using the SmartPill wireless motility capsule
Regional gut pH Day 28 Measured using the SmartPill wireless motility capsule
Mood Day 28 Hospital anxiety and depression scale
Faecal gut microbiota (alpha- and beta-diversity) Day 28 Measured by 16S community profiling (Illumina Miseq) of bacterial genomic DNA isolated from participant stool samples
Faecal short-chain fatty acids (SCFA) Day 28 Measured by gas liquid chromatography of stool sample
Dietary intake Week 4 7-day food diary
Dietary metabolites (various) Day 28 Measured in blood sample
Faecal volatile organic compounds Day 28 Measured by gas-chromatography mass-spectrometry of stool samples
Gut symptoms week 4 Gastrointestinal symptoms rating scale (7-day; questionnaire)
Quality of life Day 28 SF-36 questionnaire
Particle size of masticated snack foods Day 28 Mechanical sieving and laser diffraction of masticated snack foods
Stool frequency Week 4 Bristol stool form scale(7-day; questionnaire)
Whole gut transit time Day 28 Measured using the SmartPill wireless motility capsule
Faecal water Day 28 Measured by lyophilization of stool sample
Physical activity Day 28 Recent physical activity questionnaire
Trial Locations
- Locations (1)
King's College London Waterloo Campus
🇬🇧London, United Kingdom