Clinical trial NCT03369548: CABALA Diet & Health Study
Official title: CirculAting Bile Acids as Biomarkers of Metabolic Health - Linking microbiotA, Diet and Health
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Healthy
Keywords: Bile acids
Lipid metabolism
Cholesterol
Probiotics
Polyphenols
Prebiotics
Gut bacteria
Gut microbiota
Lead sponsor: University of Reading
Sponsor class: OTHER
Collaborators: name: University College Cork
name: Fondazione Edmund Mach
name: Università degli Studi dell'Insubria
First posted: 2017-12-12
Enrollment: 64
Sex: ALL
Minimum age (years): 25
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

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.


Eligibility criteria: Inclusion Criteria:

* 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

Exclusion Criteria:

* 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

Primary outcomes:
measure: Circulating bile acids
timeFrame: Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8
Secondary outcomes:
measure: Blood lipid profile
timeFrame: Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8
measure: Glucose response
timeFrame: Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8
measure: Insulin response
timeFrame: Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8
measure: C-peptide
timeFrame: Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8
measure: Inflammatory markers
timeFrame: Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8
measure: Gut hormones
timeFrame: Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8
measure: Metabolomics
timeFrame: Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8
measure: Nitric Oxide
timeFrame: Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8
measure: Cell-adhesion molecules
timeFrame: Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8
measure: Short-chain fatty acids
timeFrame: Chronic and acute effects: Fasting and 6-hour postprandial response and faecal sample at both baseline and week 8
measure: LDL receptor expression
timeFrame: This will be measured at baseline
measure: Genotyping of bile acid receptor gene
timeFrame: This will be measured at baseline
measure: Platelets
timeFrame: Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8
measure: Gut microbiota
timeFrame: At baseline and week 8
measure: Bile acid excretion
timeFrame: At baseline and week 8
measure: Energy excretion
timeFrame: At baseline and week 8
measure: Urine metabolites
timeFrame: At baseline and week 8
measure: Blood pressure and heart rate
timeFrame: Chronic and acute effects: Fasting and 6-hour postprandial response at both baseline and week 8
measure: Body composition
timeFrame: At baseline and week 8
Other outcomes:
Locations:
city: Reading
country: United Kingdom
facility: Hugh Sinclair Unit of Human Nutrition, Department of Food and Nutritional Sciences, University of Reading
state: Berkshire
Study officials:
affiliation: University of Reading
name: Julie A Lovegrove, Professor
role: PRINCIPAL_INVESTIGATOR
References: