Evidence map›Paper›PMID 42894232›Full record

Trial reportTrials2026

Gut Regulated Associations of Neuronal Signalling in High Blood Pressure (GRAINS-BP): a double-blinded randomised crossover placebo-controlled trial.

Malindi Welathanthree, Matthew Snelson, Donggyu Rim, Brendan McCarthy, Gianni Sesa-Ashton, David G S Farmer, Chaoran Yang, Jianan Lu, Phoebe T T Cheong, Matthew P Pase and 8 more

Abstract readRandomized Controlled Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in Trials, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

18 authors.

Malindi WelathanthreeHypertension Research Laboratory, Victorian Heart Institute, Monash University, Clayton, Australia.
Matthew SnelsonHypertension Research Laboratory, Victorian Heart Institute, Monash University, Clayton, Australia.
Donggyu RimCardiometabolic Health and Exercise Physiology, Baker Diabetes and Heart Institute, Melbourne, Australia.
Brendan McCarthyCardiometabolic Health and Exercise Physiology, Baker Diabetes and Heart Institute, Melbourne, Australia.
Gianni Sesa-AshtonCardiometabolic Health and Exercise Physiology, Baker Diabetes and Heart Institute, Melbourne, Australia.
David G S FarmerHuman Neurophysiology Lab, Department of Neuroscience, Monash University, Melbourne, Australia.
Chaoran YangHypertension Research Laboratory, Victorian Heart Institute, Monash University, Clayton, Australia.
Jianan LuHypertension Research Laboratory, Victorian Heart Institute, Monash University, Clayton, Australia.
Phoebe T T CheongHypertension Research Laboratory, Victorian Heart Institute, Monash University, Clayton, Australia.
Matthew P PaseSchool of Psychological Science, Turner Institute for Brain and Mental Health, Monash University, Melbourne, Australia.
Tracy McCaffreyDigital Nutrition Lab, Department of Nutrition, Dietetics and Food, Monash University, Melbourne, Australia.
Francis J HaVictorian Heart Hospital, Melbourne, Australia.
Sushil DhitalFood Engineering and Nutrition Lab, Department of Chemical Engineering, Monash University, Melbourne, Australia.
Esther DavisVictorian Heart Hospital, Melbourne, Australia.
Elisabeth LambertSchool of Health Science and Iverson Health Innovation Research Institute, Swinburne University of Technology, Melbourne, Australia.
Vaughan G MacefieldHuman Neurophysiology Lab, Department of Neuroscience, Monash University, Melbourne, Australia.
Francine Z Marques *Hypertension Research Laboratory, Victorian Heart Institute, Monash University, Clayton, Australia.
Rikeish R Muralitharan *Hypertension Research Laboratory, Victorian Heart Institute, Monash University, Clayton, Australia. rikeish.muralitharan@monash.edu.ORCID https://orcid.org/0000-0002-7577-2123

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundHypertension affects 1 in 3 Australian adults and is a major contributor to stroke and myocardial infarction. Despite the availability of various medications, over 50% of patients struggle to control their blood pressure (BP) due to nonadherence, difficulty finding the right treatment, or avoidance of medication. Diet plays a key role in cardiovascular health, with high-fiber intake shown to lower BP through the production of short-chain fatty acids (SCFAs), metabolites formed during fiber fermentation. A previous clinical trial found that incorporating a specific type of resistant starch - high amylose maize starch enriched with acetate and butyrate (HAMSA/B) - significantly reduced blood pressure in hypertensive patients. While the exact mechanism remains unclear, SCFAs may influence BP via the gut-brain axis by reducing muscle sympathetic nerve activity (MSNA), which has vasoconstrictor function and is elevated in hypertensive individuals.

methodsThe GRAINS-BP clinical trial will recruit 29 adults with untreated hypertension (≥ 140/90 mmHg) for a double-blind, cross-over study using HAMSA/B administered as a shake delivered twice daily. The assessment period will span 48 days and include four visits at the Alfred Hospital, Melbourne, Australia. At visit 1, baseline measurement will be taken, including muscle sympathetic nerve activity (MSNA) and electrocardiogram (ECG). Participants will be randomised to the order in which they receive the placebo and HAMSA/B shake. Each intervention period will last 14 days, separated by a 20-day washout before participants cross over to the alternate treatment. At each visit, faecal, urine, and blood samples will be collected to investigate microbiome, cardiometabolic, renal, and immune profiles, respectively. Univariate and multivariate statistical analyses will be conducted to examine treatment effects and to identify correlations among microbiome, cardiometabolic, renal, and immune outcomes. DISCUSSION: This project's primary outcome is change in autonomic nervous system activity. Secondary outcomes include 24-h BP, gut microbiome composition, SCFA levels, immune cell profiles gastrointestinal transit time, quality of life, anxiety and depression symptoms, cognitive function, gut barrier integrity, and circulating micro- and nanoplastics. Findings from this study will reveal whether SCFAs reduce blood pressure by their influence on the autonomic nervous system.

trial registrationThis trial is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12625000557437).

Indexed as

Blood PressureDietary FiberHypertensionIntestinesSympathetic Nervous SystemCross-Over StudiesDouble-Blind MethodFatty Acids, VolatileHumansResearch DesignSignal TransductionTime FactorsTreatment OutcomeVictoriaDietary FiberFatty Acids, VolatileDietFibreGut-brain axisGut microbiomeHypertensionRandomised controlled trialResistant starchesShort-chain fatty acidsSympathetic nerve activity

Identifiers

PMID42894232
PMCPMC13679180

What OpenQuestion holds

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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.