ANZCTR - Registration

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Trial registered on ANZCTR

Registration number

ACTRN12626001285347

Ethics application status

Approved

Date submitted

12/10/2026

Date registered

27/10/2026

Date last updated

27/10/2026

Date data sharing statement initially provided

27/10/2026

Date results provided

27/10/2026

Type of registration

Retrospectively registered

Titles & IDs

Public title

An experiment to observe the blood pressure and measure the acetate level in the blood of healthy young adults after taking lactulose syrup for a week.

Scientific title

The effect of weeklong lactulose ingestion on blood pressure and plasma acetate concentration in healthy young adults - a randomised controlled trial

Additional trial identifiers [1]

Nil

Universal Trial Number (UTN)

Trial acronym

Related trial records

Health condition

Health condition(s) studied:

blood pressure

Condition category

Condition code

Cardiovascular

Normal development and function of the cardiovascular system

Intervention/exposure

Study type

Interventional

Description of the intervention or exposure

The intervention is 20 mL of lactulose syrup (Actilax™, Mylan, USA) taken twice daily for one week.
The intervention is delivered by an Honours research student under the supervision of a cardiologist.
The intervention is given to the participants in the Physiology building of Monash University and participants take the syrup home to self administer twice per day.
The intervention is a viscous liquid that is consumed neat, without requiring any other liquid to wash it down. Because the intervention is taken home, and consumed by the participant there, adherence to the intervention cannot be directly supervised. Rather, compliance with the intervention is a self-reported honesty system.

Intervention code [1]

Treatment: Other

Description of the comparator or control

The comparator is 20 mL of glucose syrup (Queen, Australia) taken twice daily for one week.
The comparator is given to the participants in the Physiology building of Monash University and participants take the syrup home to self administer twice per day.
The comparator is a viscous liquid that is consumed neat, without requiring any other liquid to wash it down. Because the comparator is taken home, and consumed by the participant there, adherence to the comparator cannot be directly supervised. Rather, compliance with the comparator is a self-reported honesty system.

Control group

Active

Outcomes

Primary outcome [1]

Mean systolic blood pressure

Timepoint [1]

Measured twice. Once at the end of taking 1 week of intervention syrup twice per day, and once at the end of taking 1 week of comparator syrup twice per day. The order is randomised and blinded.

Secondary outcome [1]

Mean diastolic blood pressure

Timepoint [1]

Measured twice. Once at the end of taking 1 week of intervention syrup twice per day, and once at the end of taking 1 week of comparator syrup twice per day. The order is randomised and blinded.

Secondary outcome [2]

Plasma acetate concentration.

Timepoint [2]

Three time-points: baseline, after 1 week of intervention, and after 1 week of comparator. The order of receiving intervention or placebo is randomised and blinded.

Eligibility

Key inclusion criteria

Healthy volunteers.
Aged 18 years and over.
No history of hypertension and not taking anti-hypertensive medications.

Minimum age

18 Years

Maximum age

40 Years

Sex

Both males and females

Healthy volunteers

Yes

Key exclusion criteria

Hypertension

Study design

Purpose of the study

Prevention

Allocation to intervention

Randomised controlled trial

Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)

Randomisation was performed by a non-blinded investigator (A.J.W.) using the random number generator function of Microsoft Excel to allocate participants to active or placebo arms, and treatment allocations were entered into the RedCAPS database. A second investigator (K.J.B.) was unblinded to be able to aliquot plasma samples and code them as lactulose or glucose placebo treated specimens for the acetate assay. All other investigators, in particular the Honours student administering the experiment, were blinded to treatment allocation until all participants had completed all aspects of the protocol and the RedCAPS database had been locked.

Methods used to generate the sequence in which subjects will be randomised (sequence generation)

Computer-generated random sequence

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

Intervention assignment

Crossover

Other design features

Phase

Not Applicable

Type of endpoint/s

Efficacy

Statistical methods / analysis

Recruitment

Recruitment status

Completed

Date of first participant enrolment

Anticipated

Actual

14/04/2022

Date of last participant enrolment

Anticipated

Actual

11/08/2022

Date of last data collection

Anticipated

Actual

26/08/2022

Sample size

Target

Accrual to date

Final

Recruitment in Australia

Recruitment state(s)

VIC

Funding & Sponsors

Funding source category [1]

University

Name [1]

Medical School, Monash University

Address [1]

Country [1]

Australia

Primary sponsor type

University

Name

Monash University

Address

Country

Australia

Secondary sponsor category [1]

None

Name [1]

Address [1]

Country [1]

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

Monash University Human Research Ethics Committee

Ethics committee address [1]

https://www.monash.edu/researchoffice/ethics

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

28/01/2022

Approval date [1]

08/02/2022

Ethics approval number [1]

30082

Summary

Brief summary

Background: High blood pressure (hypertension) is very common, and is a major cause of human disease and death. In particular high blood pressure is a major cause of heart disease, kidney disease and stroke.  The body's control of blood pressure is very complex. The kidney, the blood vessels, the heart and a number of hormones are known to be involved in blood pressure control. Recently, there has been speculation about a possible role for bacteria within the large bowel (colon) in the control of blood pressure. Specifically, short-chain fatty acids ( acetate, butyrate, priopionate) produced by colonic bacteria are theorised to have a possible role in BP control.

This experiment: We will study 30 healthy adults under the age of 40. 
Each participant will take part for two weeks. Each research participant will consume 20mL twice per day of a sugary liquid - either glucose or lactulose syrup for the first week. The participant will then swap to consume the other syrup for the second week. This is called a cross-over design study. At three times during the study, each participant will be weighed, and will undergo a 24 hour blood pressure monitor and will also have blood drawn for measurement of substances relevant to the experiment, including acetate. This will be on days 0, 7 and 14 of the study.
 
Statistical analysis: There are two end-points to be measured and analysed: acetate level in the blood, and blood pressure information. Specifically the following variables will be compared: 1. Serum acetate 2. Average systolic BP 3. Average diastolic BP. These will be compared for the three time points by a statistical test called ANOVA. We will analyse for differences in these data at the end of the lactulose week, and at the end of the glucose week.

Potential significance: If the study does demonstrate elevation of acetate levels, and/or lowering of blood pressure then this may support the inclusion of larger amount of indigestible carbohydrate into the human diet.

Trial website

Trial related presentations / publications

Public notes

Contacts

Principal investigator

Name

A/Prof Anthony White

Address

Victorian Heart Institute, Blackburn Road, Clayton VIC 3168

Country

Australia

Phone

+61 3 7511 1680

Fax

[email protected]

Contact person for public queries

Name

Anthony White

Address

Victorian Heart Institute, Blackburn Road, Clayton VIC 3168

Country

Australia

Phone

+61 3 7511 1680

Fax

[email protected]

Contact person for scientific queries

Name

Anthony White

Address

Victorian Heart Institute, Blackburn Road, Clayton VIC 3168

Country

Australia

Phone

+61 3 7511 1680

Fax

[email protected]

Data sharing statement

Will the study consider sharing individual participant data?

What supporting documents are/will be available?

No Supporting Document Provided

Results publications and other study-related documents

Documents added manually

Type	Is Peer Reviewed?	DOI	Citations or Other Details	Attachment
Study results article	No			Lactulose study protocol and results for ANZCTR.docx

Documents added automatically

No additional documents have been identified.

Trial Review

Documents added manually

Documents added automatically