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Trial registered on ANZCTR


Registration number
ACTRN12619000813189
Ethics application status
Approved
Date submitted
8/05/2019
Date registered
4/06/2019
Date last updated
7/07/2020
Date data sharing statement initially provided
4/06/2019
Date results information initially provided
7/07/2020
Type of registration
Prospectively registered

Titles & IDs
Public title
Effects of intestinal Amarasate™ (a bitter hops extract) on gut function in healthy, lean volunteers.

Scientific title
Effects of intraduodenal Amarasate™ extract (bitter agonist), on upper gastrointestinal (GI) functions and energy intake in healthy, lean volunteers.
Secondary ID [1] 298001 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Type 2 Diabetes 312431 0
Healthy human gastrointestinal physiology 312432 0
Obesity 312434 0
Condition category
Condition code
Diet and Nutrition 310987 310987 0 0
Obesity
Oral and Gastrointestinal 310988 310988 0 0
Normal oral and gastrointestinal development and function
Metabolic and Endocrine 310989 310989 0 0
Diabetes

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The intervention in this study consists of an intraduodenal bolus administration of hop extract (Amarasate) or control solution, after which gut motility, gut hormone concentrations, appetite perceptions and energy intake will be measured. Studies will be carried out at the Clinical Research Facility, Adelaide Medical School, University of Adelaide, by team members trained in the required techniques and procedures. All tests will be performed while the participant attends the Research Facility, in response to the acute interventions described below, hence, no issues with compliance with the intervention are anticipated.

Subjects enrolled into the study will receive, in randomized, double blind fashion either (i) 100 mg Amarasate extract, (ii) 250 mg Amarasate extract, or (iii) Canola oil (control) on 3 separate visits. Each visit will last 5hrs in duration, and will be separated by 3-7 days. Subjects will be asked to consume a standardised dinner meal (McCain beef lasagne) the night before each visit by no later than 6pm, and then refrain from oral consumption of solids and liquids, except water, as well as any medications. This will be confirmed in the morning of the study by questioning the participant. After fasting for 14 hrs overnight and refraining from exercise and alcohol for 24 hrs, subjects will arrive at the laboratory at 8am. Upon arrival, subjects will be intubated with a 17-channel manometric catheter that will be inserted through an anaesthetised nostril and allowed to pass through the stomach and into the duodenum by peristalsis. The manometric catheter consists of 16 side holes spaced at 1.5 cm intervals, measuring pressures in the antrum, pylorus and duodenum (APD pressures). An additional channel (with the side hole positioned approx 14 cm distal to the pylorus when the catheter is in position) is used for intraduodenal administration of amarasate or control. The correct positioning of the catheter will be maintained by continuous measurement of the transmucosal potential difference (TMPD) between the most distal antral channel and the most proximal duodenal channel. All manometric channels will be perfused with degassed, distilled water, except for the two TMPD channels, which will be perfused with degassed 0.9% saline, at 0.15 ml/min. An intravenous cannula will be placed into a right forearm vein for regular blood sampling to measure plasma hormone concentrations. Once the catheter has been positioned correctly, fasting motility will be monitored continuously, and immediately after the end of phase III activity of the fasting migrating motor complex (MMC), during a period of motor quiescence (t=-10 – -1 min), a ~9 ml venous blood sample (baseline) will be taken, and the subject will complete a visual analogue scale questionnaire (VAS) to assess appetite-related perceptions (fullness, hunger, etc.) and symptoms (nausea and bloating). At t = -1 min (during phase I of the MMC), the bolus dose (either (i), (ii), or (iii) as outlined above) will be administered in ~1 min. APD pressures will be measured continually over the following 180-min period. Blood samples will be collected and VASs completed every 10 min from t = 10 to 30 min, then every 15 min from t = 30 to 60 min, and then every 30 min until t = 180 min. At t = 180 min, the manometric catheter will be removed and subjects will be presented with a cold, buffet-style meal. Subjects will be allowed 30 min to freely consume food until they are comfortably full. At t = 210 min another blood sample will be taken, and VAS administered. The intravenous cannula will then be removed and subjects will be allowed to leave the laboratory. A total of 99 ml of blood will be taken on each study day (297 ml over all study visits).
Intervention code [1] 314227 0
Treatment: Other
Comparator / control treatment
Canola oil
Control group
Placebo

Outcomes
Primary outcome [1] 319793 0
Plasma concentrations of gastrointestinal hormones, e.g. CCK, GLP-1, PYY and ghrelin, will be assessed by Enzyme-linked Immunosorbent Assay (ELISA) or Radio Immunosorbent Assay (RIA).

This intervention is of an exploratory nature to characterise the effects of varying doses of amarasate. As such, it is unknown which plasma concentrations of gastrointestinal hormones may prove to be of importance. Hence these have been grouped into one composite primary outcome.
Timepoint [1] 319793 0
At t = -10 min, 10 minute intervals from t= 10- 30 min, 15 min intervals from t= 30 - 60 min, 30 min intervals from t= 60 - 180 min, and at t= 210 min.
Primary outcome [2] 319794 0
Antropyloroduodenal pressures will be measured using a 17-channel manometric assembly (Dentsleeve, Mui Scientific).
Timepoint [2] 319794 0
Baseline (t = -10 - 0 min) and after intraduodenal administration (t = 0 - 180 min).
Secondary outcome [1] 369550 0
Energy intake at the buffet meal. The weight of the foods will be recorded before and after being offered to the subjects and energy intake and macronutrient composition calculated subsequently using commercially available software (Foodworks, Xyris Software, Highgate Hill, QLD, Australia).
Timepoint [1] 369550 0
180 min after the intraduodenal administration, for 30 minutes (t=180-210min).
Secondary outcome [2] 369551 0
Appetite sensations (hunger, fullness, desire to eat, amount of food the subject thinks they could eat) and gastrointestinal symptoms (nausea, bloating) will be measured using a 100mm Visual Analogue Scale (VAS) questionnaire. This questionnaire has been extensively employed in published studies conducted by the investigator.

This intervention is of an exploratory nature to characterise the effects of varying doses of amarasate. As such, it is unknown which appetite sensations and gastrointestinal symptoms may prove to be of importance. Hence these have been grouped into one composite secondary outcome.
Timepoint [2] 369551 0
At t = -10 min, 10 minute intervals from t= 10- 30 min, 15 min intervals from t= 30 - 60 min, 30 min intervals from t= 60 - 180 min, and at t= 210 min.
Secondary outcome [3] 369881 0
Plasma concentrations of Insulin, Glucagon, C-peptide will be assessed by Enzyme-linked Immunosorbent Assay (ELISA) or Radio Immnunosorbent Assay (RIA).

This intervention is of an exploratory nature to characterise the effects of varying doses of amarasate. As such, it is unknown which plasma concentrations of hormones may prove to be of importance. Hence these have been grouped into one composite secondary outcome.

Timepoint [3] 369881 0
At t = -10 min, 10 minute intervals from t= 10- 30 min, 15 min intervals from t= 30 - 60 min, 30 min intervals from t= 60 - 180 min, and at t= 210 min.

Eligibility
Key inclusion criteria
A total of 12 healthy, lean (BMI 19-25 kg/m2) male subjects, aged between 18 - 60 years will be included. Subjects will be required to be weight stable (ie <5% fluctuation) at study entry, which will be ascertained by a stable body weight in the preceding 4 weeks.
Minimum age
18 Years
Maximum age
60 Years
Sex
Males
Can healthy volunteers participate?
Yes
Key exclusion criteria
Significant GI symptoms, disease or surgery
Use of prescribed or non-prescribed medications (including vitamins and herbal Supplements) which may affect energy metabolism, GI function, body weight or appetite (eg domperidone, cisapride, anticholinergic drugs (eg atropine), metoclopramide, erythromycin, hyoscine, orlistat, green tea extracts, Astragalus, St Johns Wort etc.)
Lactose intolerance/other food allergy(ies), including hops allergy, diagnosed idiopathic anaphylaxis or occupational exposure to hops (hops pickers, brewers)
Current gallbladder or pancreatic disease
Cardiovascular or respiratory diseases
Individuals with low ferritin levels (females <15 ng/mL, males <30 ng/mL), or who have donated blood in the 12 weeks prior to taking part in the study
Any other illnesses as assessed by the investigator (including chronic illnesses not explicitly listed above)
High performance athletes
Current intake of > 2 standard drinks on > 5 days per week
Current smokers of cigarettes/cigars/marijuana
Recreational drug use
Current intake of any illicit substance
Vegetarians
Inability to tolerate nasogastric tube
Inability to comprehend study protocol
Restrained eaters (score >12 on the 3-factor eating questionnaire)

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation involves contacting the holder of the randomisation table (study assistant) to inform them of the next subjects details and study dates. The unblinded study assistant is therefore responsible for allocating a randomly generated treatment sequence to the subject and preparing the intraduodenal bolus for administration on each study day.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The randomisation is generated using a randomization plan generator available at www.randomization.com
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint/s
Pharmacodynamics
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
14/06/2019
Actual
19/06/2019
Date of last participant enrolment
Anticipated
20/11/2019
Actual
12/08/2019
Date of last data collection
Anticipated
16/12/2019
Actual
30/08/2019
Sample size
Target
12
Accrual to date
Final
15
Recruitment in Australia
Recruitment state(s)
SA

Funding & Sponsors
Funding source category [1] 302526 0
Government body
Name [1] 302526 0
National Health and Medical Research Council (NHMRC)
Country [1] 302526 0
Australia
Primary sponsor type
Individual
Name
Professor Christine Feinle-Bisset
Address
Adelaide Medical School | Faculty of Health and Medical Sciences
The University of Adelaide
Level 5, Adelaide Health and Medical Sciences Building
Cnr North Terrace and George Street
Adelaide
South Australia 5005
Country
Australia
Secondary sponsor category [1] 302453 0
Individual
Name [1] 302453 0
Professor Michael Horowitz
Address [1] 302453 0
Adelaide Medical School | Faculty of Health and Medical Sciences
The University of Adelaide
Level 6, Adelaide Health and Medical Sciences Building
Cnr North Terrace and George Street
Adelaide
South Australia 5005
Country [1] 302453 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 303177 0
Central Adelaide Local Health Network Human Research Ethics Committee
Ethics committee address [1] 303177 0
Level 3, Roma Mitchell Building
136 North Terrace
Adelaide SA 5000
Ethics committee country [1] 303177 0
Australia
Date submitted for ethics approval [1] 303177 0
21/06/2018
Approval date [1] 303177 0
03/08/2018
Ethics approval number [1] 303177 0
CALHN Reference number: R20180631 HREC/18/CALHN/416

Summary
Brief summary
The purpose of this trial is to investigate the dose-related effects of small intestinal administration of the bitter agonist, Amarasate, on the motor and hormone functions of the upper gastrointestinal tract, appetite, and energy intake. We have found previously that specific dietary nutrients, when given into the small intestine in small amounts (and so not contributing significantly to overall energy intake) have the unique ability to substantially stimulate gastrointestinal functions leading to marked energy intake suppression. There has been a recent interest in the effects of bitter compounds, some of which also occur in the diet, including thio-urea compounds in certain vegetables or fruit, or quinine in tonic water, with reported effects on gut functions and energy intake suppression.
This study aims to characterise the dose-related effects of amarasate (a natural extract from a hop cultivar), when delivered to the small intestine, in an effort to identify an optimal dose for beneficial effect on the outcomes mentioned herein.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 92754 0
Prof Christine Feinle-Bisset
Address 92754 0
Adelaide Medical School | Faculty of Health and Medical Sciences
The University of Adelaide
Level 5, Adelaide Health and Medical Sciences Building
Cnr North Terrace and George Street
Adelaide
South Australia 5005
Country 92754 0
Australia
Phone 92754 0
+61 8 8313 6053
Fax 92754 0
Email 92754 0
[email protected]
Contact person for public queries
Name 92755 0
Prof Christine Feinle-Bisset
Address 92755 0
Adelaide Medical School | Faculty of Health and Medical Sciences
The University of Adelaide
Level 5, Adelaide Health and Medical Sciences Building
Cnr North Terrace and George Street
Adelaide
South Australia 5005
Country 92755 0
Australia
Phone 92755 0
+61 8 8313 6053
Fax 92755 0
Email 92755 0
[email protected]
Contact person for scientific queries
Name 92756 0
Prof Christine Feinle-Bisset
Address 92756 0
Adelaide Medical School | Faculty of Health and Medical Sciences
The University of Adelaide
Level 5, Adelaide Health and Medical Sciences Building
Cnr North Terrace and George Street
Adelaide
South Australia 5005
Country 92756 0
Australia
Phone 92756 0
+61 8 8313 6053
Fax 92756 0
Email 92756 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
The datasets generated during and/or analysed during the current study are not publicly available due to the ethical statement and informed consent that require privacy of data


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
TypeIs Peer Reviewed?DOICitations or Other DetailsAttachment
Plain language summaryNo In healthy men, intraduodenal administration of Am... [More Details]

Documents added automatically
No additional documents have been identified.