Nutrition, Healthy
Conditions
Keywords
broccoli, sulforaphane, probiotic, gut microbiota, L. plantarum, bioavailability, cross-over trial
Brief summary
Broccoli has the precursor of an active compound (sulforaphane) that has shown a wide range of health promoting benefits. Sulforaphane formation depends on the conversion of glucoraphanin (precursor) by myrosinase enzyme. Thus, the bioavailability of sulforaphane is affected by myrosinase activity. Some bacteria, such as L. plantarum (probiotic), have shown they can also convert glucoraphanin to sulforaphane in vitro. This study investigates the effect of short-term L. plantarum supplementation on broccoli sulforaphane bioavailability in humans using a randomised double-blind placebo-controlled crossover trial.
Detailed description
Brassicas (i.e. broccoli, kale, cabbage) are a group of edible plants that contain a phytochemical called glucoraphanin that upon enzymatic hydrolysis forms the bioactive form sulforaphane. Sulforaphane has shown consistent in vitro and in vivo (animals) anti-cancer activity. The enzyme responsible for this conversion is called myrosinase; however, the enzymatic activity of myrosinase can be affected by several biological factors (e.g. plant variety, growth conditions, etc...) and food processing (e.g. cooking, drying, etc...). Broccoli is one of the richest sources of glucoraphanin, but its myrosinase activity can be easily lost during cooking: 10 minutes at 70 °C reduces the enzyme activity by 95%. This means broccoli prepared this way will contain little to no biologically active sulforaphane. Therefore, is important to find strategies to increase the bioavailability of sulforaphane in broccoli and other brassicas for human consumption. Certain bacteria have shown myrosinase-like activity and were able to convert glucoraphanin to sulforaphane in vitro, one of these bacteria is Lactiplantibacillus plantarum. This bacterium is present in the human gut, however, there is a large biological variability in the prevalence of this bacteria between individuals. Several human studies have demonstrated that chronic (>1 week) consumption of probiotic supplements containing L. plantarum was able to increase the presence of this bacterium in human gut participants. Thus, the investigators aim to test if supplementing participants with L. plantarum will increase the bioavailability of sulforaphane, compared to placebo.
Interventions
DIETARY_SUPPLEMENTBroccoli sprouts extract supplementation
Intake of broccoli sprouts extract supplement (Brand: Source Naturals, Scotts Valley, CA 95066 - USA) in an acute dose (84 umol of glucoraphanin) before and after 2 weeks of probiotic or placebo supplementation, to assess sulforaphane bioavailability measured in urine metabolites
Sponsors
University of Exeter
The University of Queensland
PepsiCo, Inc.
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Intervention model description
Randomised Double-blind Placebo-controlled Crossover Study
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* healthy adults (male and female) * age range of 18-65 years * BMI range of 18-30 kg/m2
Exclusion criteria
* have been on a course of antibiotics within the period of the past 3 months. * have allergies or intolerance towards probiotic substances or broccoli used in the study and/or food intolerances associated with gastrointestinal upset. * have been taking pre- or probiotics supplements regularly during the last month prior (this does not include foods containing probiotics and/or prebiotics foods) * are following any restricting diet (e.g., vegan, FODMAP, etc.). * have a gastrointestinal inflammatory condition (e.g., irritable bowel syndrome, inflammatory bowel diseases, coeliac diseases, constipation, etc.). * have a medical condition or take medication for any heart, endocrine, or metabolic condition, such as high blood pressure, high cholesterol, insulin resistance, or diabetes, or autoimmune disease. * are a pregnant and/or breastfeeding.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Bioavailability of sulforaphane | From baseline to the end of each condition at 2 weeks, followed by 2 weeks of wash-out, and before and after the next condition | Bioavailability (%) of sulforaphane (will be estimated by dividing the cumulative amount of sulforaphane mercapturic acid excreted in urine in 24 h by the consumed amount of glucoraphanin (Vermeulen et al., 2008)) before and after chronic consumption of L. plantarum compared with placebo. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Sulforaphane pharmacokinetics: Area under the curve | From baseline to the end of each condition at 2 weeks, followed by 2 weeks of wash-out, and before and after the next condition. | Measurement of the definite integral of the concentration of sulforaphane (and its metabolites) in blood plasma as a function of time. |
| Sulforaphane pharmacokinetics: Cmax | From baseline to the end of each condition at 2 weeks, followed by 2 weeks of wash-out, and before and after the next condition. | Measurement of the maximum plasma concentration (Cmax) of sulforaphane (and its metabolites) indicating the value of the highest concentrations reached in the plasma. |
| Sulforaphane pharmacokinetics: Tmax | From baseline to the end of each condition at 2 weeks, followed by 2 weeks of wash-out, and before and after the next condition. | Measurement of the time taken for sulforaphane (and its metabolites) to reach the maximum concentration (Cmax) after administration of the supplement that needs to be absorbed. |
Countries
United Kingdom
Contacts
PRINCIPAL_INVESTIGATORLuciana Torquati, PhD
University of Exeter
Outcome results
None listed