Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12625000557437
Ethics application status
Approved
Date submitted
17/04/2025
Date registered
30/05/2025
Date last updated
30/05/2025
Date data sharing statement initially provided
30/05/2025
Type of registration
Prospectively registered

Titles & IDs
Public title
Study on How Nerve Signalling is Affected by a High-Fibre Supplement in Untreated Hypertensive Individuals.
Scientific title
A Randomised Controlled Trial Investigating the Effects of HAMSAB, a High-Fibre Supplement, on Gut-Brain Axis and Blood Pressure Regulation in Untreated Hypertensive Individuals.
Secondary ID [1] 314209 0
None
Universal Trial Number (UTN)
Trial acronym
GRAINS-BP
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Hypertension 337105 0
Condition category
Condition code
Cardiovascular 333526 333526 0 0
Hypertension

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The substance being given to the participants in this study is HAMSA/B, an amylose starch that has been acetylated and butyrylated. Participants will be given 40g/day in two serves (20g/serve) in the morning and night along side their usual breakfast and dinner for 14 days. We have commissioned Premium Blends, a company that develops shake powder (such as protein powder), that will develop and sachet the supplement into individual serves, as well as placebo sachets with the same taste and mass. At the beginning of each intervention period, participants will be given their supplement sachets by the study coordinator at the scheduled visits. The participants will empty the contents of one sachet into the provided shaker, fill with their desired amount of water, and shake to mix, The first intervention period of 14 days, is followed by a 20 day wash out period, and then the next intervention period of a further 14 days. To monitor adherence to the intervention, we will require the participants to complete a 3-day food diary using the app 'Easy Diet Diary', as well as the return of any unused sachets.
Intervention code [1] 330826 0
Treatment: Other
Comparator / control treatment
For the placebo shakes, a waxy maize starch will be used in place of HAMSA/B. Both the placebo and intervention shakes will be the same flavour for consistency. The trial is a double-blinded crossover randomised trial. Following an eligibility check, participants will be randomised into one of two groups. One group will be given the HAMSAB shakes first and then the placebo shakes after the washout period. The other group will be given the placebo shakes first and the HAMSAB shake after the washout period. Like the HAMSAB shakes, the placebo shakes sachets will be given to the participants by the study coordinator as the scheduled visits. 40g/day of the placebo shakes will be consumed in two serves (20g/serve) in the morning and night along side their usual breakfast and dinner for 14 days.
Control group
Placebo

Outcomes
Primary outcome [1] 341120 0
Changes in the autonomic nervous system (ANS) signalling.
Timepoint [1] 341120 0
Four timepoints; 1) baseline before the beginning of interventions, 2) after first intervention period, 3) baseline 2 after washout period, and 4) after second intervention period.
Primary outcome [2] 341282 0
Changes in blood pressure.
Timepoint [2] 341282 0
Four timepoints; 1) baseline before the beginning of interventions, 2) after first intervention period, 3) baseline 2 after washout period, and 4) after second intervention period.
Primary outcome [3] 341283 0
Changes in Heart Rate Variability (HRV)
Timepoint [3] 341283 0
Electrocardiogram will be meassured at four timepoints; 1) baseline before the beginning of interventions, 2) after first intervention period, 3) baseline 2 after washout period, and 4) after second intervention period. Heart rate monitoring device will be worn twice throughout the trial, 14 days at a time.
Secondary outcome [1] 446345 0
Changes in microbiome.
Timepoint [1] 446345 0
Four timepoints; 1) baseline before the beginning of interventions, 2) after first intervention period, 3) baseline 2 after washout period, and 4) after second intervention period.
Secondary outcome [2] 447015 0
Changes in immune profiles.
Timepoint [2] 447015 0
Four timepoints; 1) baseline before the beginning of interventions, 2) after first intervention period, 3) baseline 2 after washout period, and 4) after second intervention period.
Secondary outcome [3] 447016 0
Correlation between autonomic nervous system signalling and difference in moods.
Timepoint [3] 447016 0
Four timepoints; 1) baseline before the beginning of interventions, 2) after first intervention period, 3) baseline 2 after washout period, and 4) after second intervention period.
Secondary outcome [4] 447017 0
Gastrointestinal transit time.
Timepoint [4] 447017 0
Four timepoints; 1) baseline before the beginning of interventions, 2) after first intervention period, 3) baseline 2 after washout period, and 4) after second intervention period.
Secondary outcome [5] 447018 0
Changes in renal function.
Timepoint [5] 447018 0
Four timepoints; 1) baseline before the beginning of interventions, 2) after first intervention period, 3) baseline 2 after washout period, and 4) after second intervention period.
Secondary outcome [6] 448172 0
Correlation between autonomic nervous system signalling and gastrointestinal symptoms.
Timepoint [6] 448172 0
Four timepoints; 1) baseline before the beginning of interventions, 2) after first intervention period, 3) baseline 2 after washout period, and 4) after second intervention period.
Secondary outcome [7] 448173 0
Correlation between autonomic nervous system signalling and quality of sleep.
Timepoint [7] 448173 0
Four timepoints; 1) baseline before the beginning of interventions, 2) after first intervention period, 3) baseline 2 after washout period, and 4) after second intervention period.
Secondary outcome [8] 448174 0
Correlation between autonomic nervous system signalling and quality of life.
Timepoint [8] 448174 0
Four timepoints; 1) baseline before the beginning of interventions, 2) after first intervention period, 3) baseline 2 after washout period, and 4) after second intervention period.
Secondary outcome [9] 448177 0
Exposure to chemicals associated with plastics
Timepoint [9] 448177 0
Four timepoints; 1) baseline before the beginning of interventions, 2) after first intervention period, 3) baseline 2 after washout period, and 4) after second intervention period.

Eligibility
Key inclusion criteria
1) BMI 18.5-35 kg/m2;
2) BP categorised as hypertension (systolic BP of 140 mmHg and/or diastolic BP of 90 mmHg), defined according to the Australian Heart Foundation guidelines;
3) Intake of whole grains lower than 2 servings per day (females) and 3 servings per day (males);
Minimum age
18 Years
Maximum age
75 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
1) Use of anti-hypertensive medication (current or in the past 4 weeks);
2) Office systolic BP greater than 160 and/or diastolic BP greater than 100 mmHg;
3) Recent use of oral antibiotics (for the past 3 months);
4) Recent use of probiotics (for the 4 weeks);
5) Current use of laxatives;
6) Presence of type 1 or type 2 diabetes;
7) Pregnancy or plans to conceive during the course of the trial;
8) Presence of gastrointestinal diseases (including inflammatory bowel disease, lactose intolerance, celiac disease, chronic constipation, chronic pancreatitis or other malabsorption disorder) and/or diagnosed mental health disorders (anxiety and depression);
9) Compromised immune system, regular use of steroid treatment, or use of GLP-1 agonists;

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)
A random sequence will be implemented to reduce the predictability of the randomisation. This will be automatically assigned in RedCap using an Excel spreadsheet. The study coordinator will not have access to the spreadsheet.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Patients will be randomised using sequence generation based on risk factors used for stratification, including sex, age, and BMI. Participants will be given an ID. The data manager will generate the allocation sequence, and the study coordinator will assign participants to the intervention based on the RedCap result.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s

Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
23/06/2025
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
29
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC

Funding & Sponsors
Funding source category [1] 318725 0
Government body
Name [1] 318725 0
NHMRC Investigator Grant
Country [1] 318725 0
Australia
Primary sponsor type
Individual
Name
Professor Francine Marques - Monash University
Address
Country
Australia
Secondary sponsor category [1] 321161 0
None
Name [1] 321161 0
Address [1] 321161 0
Country [1] 321161 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 317337 0
Monash University Human Research Ethics Committee
Ethics committee address [1] 317337 0
Ethics committee country [1] 317337 0
Australia
Date submitted for ethics approval [1] 317337 0
18/03/2025
Approval date [1] 317337 0
07/05/2025
Ethics approval number [1] 317337 0

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 140730 0
Prof Francine Marques
Address 140730 0
Victorian Heart Hospital, 631 Blackburn Rd, Clayton VIC 3168
Country 140730 0
Australia
Phone 140730 0
+61 425075884
Fax 140730 0
Email 140730 0
[email protected]
Contact person for public queries
Name 140731 0
Malindi Welathanthree
Address 140731 0
Victorian Heart Hospital, 631 Blackburn Rd, Clayton VIC 3168
Country 140731 0
Australia
Phone 140731 0
+61 466 126 918
Fax 140731 0
Email 140731 0
[email protected]
Contact person for scientific queries
Name 140732 0
Dr Rikeish R. Muralitharan
Address 140732 0
Victorian Heart Hospital, 631 Blackburn Rd, Clayton VIC 3168
Country 140732 0
Australia
Phone 140732 0
+61 417968704
Fax 140732 0
Email 140732 0
[email protected]

Data sharing statement
Will the study consider sharing individual participant data?
No


What supporting documents are/will be available?

Doc. No.TypeCitationLinkEmailOther DetailsAttachment
24787Ethical approval    Ethics Approval certificate.pdf



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.