CABALA Diet & Health Study
- Conditions
- Healthy
- Interventions
- Other: CornflakesOther: OatsDietary Supplement: Lactobacillus reuteri NCIMB 30242Other: Apple
- Registration Number
- NCT03369548
- Lead Sponsor
- University of Reading
- Brief Summary
During digestion of fatty foods, the liver produces a substance called bile which helps with the absorption of fat in the gut (small intestine). Some research studies have shown that friendly bacteria that live in our gut can change the makeup of bile (referred to as bile acids) leading to a lowering of blood cholesterol levels, an important risk factor for developing heart disease. This finding has been found in people who consume diets high in dietary fibers and probiotics that enhance the growth of friendly gut bacteria, and also plant rich foods high in polyphenols (such as apples). At present, very little is known about how the makeup of bile acids can regulate blood cholesterol levels and if their measurement in blood, urine or stool samples can be used as an indicator of human health.
The aim of this study is to explore how consumption of foods which enhance the growth of friendly gut bacteria (such as probiotics, prebiotics, and plant rich foods high in polyphenols) can change the makeup of bile acids after 8 weeks. Changes in the bile acids measured in blood and stool samples will then be related to markers of health, such as blood cholesterol, glucose, insulin, vascular health and inflammatory markers.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- UNKNOWN
- Sex
- All
- Target Recruitment
- 64
- Men and women
- Aged 25-70 years
- BMI: 23-32 kg/m2
- Fasting glucose < 7 mmol/l
- Total cholesterol < 7.5 mmol/L
- Triglycerides < 2.3 mmol/L
- Habitual breakfast consumers
- Weight stable in the last three months
- Smoker
- Diabetes
- Endocrine disease
- Cardiovascular disease diagnosis
- Gastrointestinal diseases
- Pancreatic, hepatic or renal diseases
- Medications that could influence study outcomes (e.g. lipid lowering medications, anti-depressants, anticoagulants)
- Antibiotic use within the last three months
- Food allergies (e.g. gluten, dairy, apples) and intolerances (e.g. lactose)
- Alcohol or drug abuse (Drink more than 14 units of alcohol per week)
- Anemia (men:haemoglobin<130g/ L and women <120 g/L
- Planning or currently on a weight reducing program
- Pregnancy, planned pregnancy in the next year or lactating
- Irregular menstrual cycle
- Planning or currently on a weight reducing program
- Currently taking part or participation in other research studies within the last three months
- Recent blood donation or unwilling to refrain from donating blood during the study
- Regular consumption of probiotic or prebiotic food supplements or fiber based laxatives and unwilling stop consuming these for the duration of the study
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Placebo / cornflakes Cornflakes Participants will be asked to consume 40g cornflakes with semi-skimmed milk and 2 placebo capsules every day for 8 weeks. Oats / Prebiotic Oats Participants will be asked to consume 40g jumbo rolled oats with semi-skimmed milk and 2 placebo capsules every day for 8 weeks. Lactobacillus reuteri NCIMB 30242 / Probiotic Lactobacillus reuteri NCIMB 30242 Participants will be asked to consume 2 probiotic capsules and 40g cornflakes with semi-skimmed milk every day for 8 weeks. Apple/ Polyphenol Apple Participants will be asked to consume 2 Renetta Canada apples (with skin) and 2 placebo capsules every day for 8 weeks.
- Primary Outcome Measures
Name Time Method Circulating bile acids Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8 Plasma bile acid profile
- Secondary Outcome Measures
Name Time Method Nitric Oxide Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8 Fasting and postprandial concentrations of nitric oxide
Inflammatory markers Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8 Fasting blood concentrations of C-reactive protein (CRP), IL-18, IL-1β and tumour necrosis factor alpha (TNF-α)
Glucose response Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8 Fasting and postprandial blood glucose concentrations
Gut hormones Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8 Fasting and postprandial concentrations of peptide YY, Glucagon-Like Peptide 1, Fibroblast growth factor 19
Metabolomics Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8 Profile of metabolites in the blood (fasting and postprandial)
Blood lipid profile Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8 total, low density lipoprotein (LDL) and high density lipoprotein (HDL) cholesterol, triacylglycerol (TAG) and non-esterified fatty acids (NEFA)
Insulin response Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8 Fasting and postprandial blood insulin concentrations
C-peptide Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8 Fasting and postprandial blood C-peptide concentrations
Cell-adhesion molecules Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8 Fasting and postprandial concentrations of ICAM and VCAM
LDL receptor expression This will be measured at baseline LDL receptor expression in peripheral blood mononuclear cells
Platelets Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8 Platelets will be collected for in-vitro studies
Gut microbiota At baseline and week 8 Next-generation sequencing of gut bacteria and enumeration of selected bacteria using FISH (fecal samples)
Genotyping of bile acid receptor gene This will be measured at baseline Genotyping of single-nucleotide polymorphisms (SNPs) in the FXR-encoding gene NR1H4
Energy excretion At baseline and week 8 Bomb calorimetry of fecal samples
Short-chain fatty acids Chronic and acute effects: Fasting and 6-hour postprandial response and faecal sample at both baseline and week 8 Fasting and postprandial circulating short-chain fatty acids concentrations and fecal short-chain fatty acid concentrations
Bile acid excretion At baseline and week 8 Fecal bile acid concentrations
Urine metabolites At baseline and week 8 Markers of intervention foods/ supplements in urine (24h urine collection)
Blood pressure and heart rate Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8 Ambulatory blood pressure and heart rate
Body composition At baseline and week 8 Body composition measured using bio-impedance
Trial Locations
- Locations (1)
Hugh Sinclair Unit of Human Nutrition, Department of Food and Nutritional Sciences, University of Reading
🇬🇧Reading, Berkshire, United Kingdom