Effect of Yakult Ingestion on Diet-induced Insulin Resistance in Humans. A Large-cohort, Mechanistic Follow-up Study.
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Loughborough University
- Enrollment
- 56
- Locations
- 1
- Primary Endpoint
- Whole body insulin sensitivity index
Study Overview
Brief Summary
Participants will be randomly allocated to either Yakult ingestion or a control group. For the first 20 days, subjects will consume their normal diet (keeping a detailed food diary throughout). On days 21-28 they will switch to a high-fat/high-calorie diet.
The investigators hypothesise that consuming a high-fat, high-energy diet for 7 days will alter the composition of the gut microbiota and induce metabolic endotoxaemia / systemic inflammation as well as decreasing whole body insulin sensitivity (as we have shown previously). In contrast, the investigators hypothesise that consuming Yakult for 21 days before and 7 days throughout the high-fat diet will maintain a favourable gut microbiota and prevent metabolic endotoxaemia / systemic inflammation and thus maintain insulin action / insulin sensitivity.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Basic Science
- Masking
- None
Masking Description
Participants will be given a unique identifier, which will not disclose the treatment group. All biological samples will be labelled with only the unique identifier.
Eligibility Criteria
- Ages
- 18 Years to 30 Years (Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Males and females
- •Aged 18-30
- •Physically active (exercising at least 3 times per week for more than 30 min at a time)
- •Non-smoker
- •Free from cardiovascular or metabolic disease
- •Weight stable for at least 6 months
- •Normal body mass index (BMI: 18.5-24.9 kg/m2)*
- •Compliant (i.e. understands and is willing, able and likely to comply with all study requirements)
- •Note: If BMI is >24.9, but body fat % (as measured by bioelectrical impedance analysis) is below 21% in males and 31% in females, then the subject may still be recruited at the PI's discretion.
Exclusion Criteria
- •Using probiotic or prebiotic supplements within the previous 3 months
- •Vegetarians and vegans
- •Diagnosis of insulin resistance, pre-diabetes or full diabetes
- •Underweight (determined as BMI less than 18.5 kg/m2)
- •Overweight or obese (determined as BMI greater than 24.9 kg/m2)
- •Those on a calorie controlled diet or other dietary restrictions that would prevent them from consuming the probiotic treatment and high fat/high calorie diet.
- •Those who are unwilling to restrict their intake of fermented dairy products.
- •Those with known or suspected food intolerances, allergies or hypersensitivity
- •Women who are known to be pregnant or who are intending to become pregnant over the course of the study.
- •Participation in another clinical trial
- •Those who have donated blood within 3 months of the screening visit and participants for whom participation in this study would result in having donated more than 1500 ml of blood in the previous 12 months.
- •Participants who take any form of regular medication that is known to affect either the gut microbiota and/or insulin sensitivity or who have taken any antibiotics in the previous 3 months.
- •Participants who know they would not be available for all the lab visits during the 4-week study period.
Arms & Interventions
Treatment Group
Participants will receive 2 x 65mL doses of Yakult light per day, for 28 days.
Participants will consume a high-fat (65% of kilocalories) high-calorie (150% of requirements) diet from day 21 to day 28.
Intervention: Yakult light (Dietary Supplement)
Control Group
Participants will consume a high-fat (65% of kilocalories) high-calorie (150% of requirements) diet from day 21 to day 28.
Outcomes
Primary Outcomes
Whole body insulin sensitivity index
Time Frame: The change between pre- and post-high fat diet (assessed on days 21 and 28)
Assessed by oral glucose tolerance test.
Secondary Outcomes
- Fasting serum insulin concentration(Day 0, Day 21 and Day 28)
- Metabolic endotoxaemia(Day 0, Day 21 and Day 28)
- Body Mass Index(Day 0, Day 21 and Day 28)
- Fasting plasma glucose concentration(Day 0, Day 21 and Day 28)
- Markers of systemic inflammation(Day 0, Day 21 and Day 28)
- Fasting plasma triglyceride concentration(Day 0, Day 21 and Day 28)
- Incretin response to glucose ingestion(Day 0, Day 21 and Day 28)
- Microbiome analysis(Day 0, Day 21 and Day 28)
Investigators
Carl Hulston
Lecturer in Sports Nutrition
Loughborough University