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HypertensionPhase 1NCT07206303

The Effects of Bifidobacterium-based Probiotics in Reducing Blood Pressure in Middle-aged Chinese With Hypertension

A Phase 1 study testing Bifidobacterium probiotics supplementation in people with Hypertension, run by The University of Hong Kong at 1 site in Hong Kong.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
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Trial summary

The primary objective of this study is to investigate if a Bifidobacterium-based probiotic intervention would reduce clinic systolic BP in untreated middle-aged Chinese men and women with hypertension according to ACC/AHA guidelines (SBP ≥130 mm Hg) after 12 weeks of treatment. Read more about this study

Who is it for?
Ages 40 to 65 years
Conditions the study is for
Hypertension
What is being tested?
Bifidobacterium probiotics supplementation
Could I receive a placebo?
No, everyone receives an active treatment
How many people
30 participants
Where
1 siteHong Kong
Study dates
Nov 2026to Nov 2027
Phase
Phase 1
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 40 to 65 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Men or women, aged 40-65 years old.
  • Chinese residing in Hong Kong.
  • Clinic SBP ≥130mmHg according to screening measurement at baseline.
  • Untreated or not on antihypertensive medications within 4 weeks.
  • Able to provide informed consent.

Who cannot join

  • Clinic SBP >165mmHg according to screening measurement at baseline
  • Known history of diabetes, coronary artery disease, stroke, peripheral artery disease, malignancy or chronic kidney disease
  • Known history of gastrointestinal disorders including inflammatory bowel disease, irritable bowel syndrome, Helicobacter pylori infection, liver cirrhosis or long-term use of proton pump inhibitors.
  • Known increased risk of infection due to endovascular or rheumatic heart disease, endovascular grafts, congenital heart defects, endocarditis, mechanical heart valves, and permanent endovascular devices including permanent (not temporary) hemodialysis catheters, pacemakers, or defibrillators.
  • Known secondary causes of hypertension.
  • Currently taking omega-3 fatty acid supplements, probiotics, rifaximin, steroids, and antihypertensive agents within 4 weeks.
Show all 14Show fewer
  • Currently taking antibiotics within 6 months.
  • Currently taking anti-oxidant vitamins within 6 months.
  • Recent travel to tropical areas within 6 months.
  • Recent bariatric surgery, hepatic resection, intestinal resection/colectomy, or any surgery within 3 months before the study.
  • Identified higher susceptibility to infections caused by immunosuppression, such as a history of organ or hematopoietic stem cell (HSCs) transplant, neutropenia (ANC <500 cells/µl), HIV, and CD4 <200 cells/µl.
  • Known allergies to any of the components of Bifidobacterium-based probiotics supplement.
  • Women who are pregnant, or intending to become pregnant, or lactation.
  • Intending to participate or have participated in a clinical or nutritional intervention study in the last 30 days before study enrolment.

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Gary Kui-Kai Lau contact

+852 22554249

gkklau@hku.hk

Hong Kong1 site

  • The University of Hong Kong

    Hong Kong

    Gary Kui-Kai Lau, +852 22554249, gkklau@hku.hk

    Joshua Wing Kei Ho

Other trials in Hong Kong

About this study

Official title: The Effects of Bifidobacterium-based Probiotics in Reducing Blood Pressure in Middle-aged Chinese With Hypertension: a Single-arm Feasibility Pilot Study

The primary objective of this study is to investigate if a Bifidobacterium-based probiotic intervention would reduce clinic systolic BP in untreated middle-aged Chinese men and women with hypertension according to ACC/AHA guidelines (SBP ≥130 mm Hg) after 12 weeks of treatment. The investigators anticipate that this feasibility study will provide rationale to conduct a larger randomized clinical trial and preliminary data to estimate the power/ sample size of a larger RCT.

Read the detailed description

The primary objective of this study is to investigate if a Bifidobacterium-based probiotic intervention would reduce clinic systolic BP in untreated middle-aged Chinese men and women with hypertension according to ACC/AHA guidelines (SBP ≥130 mm Hg) after 12 weeks of treatment. The investigators anticipate that this feasibility study will provide rationale to conduct a larger randomized clinical trial and preliminary data to estimate the power/ sample size of a larger RCT.

The four independent but interrelated objectives of this study include:

  1. To investigate if oral administration of Bifidobacterium-based probiotic intervention will reduce clinic SBP and DBP from baseline to the end of treatment.
  2. To observe changes in 24-hour mean, daytime and nighttime SBP and DBP assessed by 24-hour ambulatory BP monitoring from baseline to the end of treatment.
  3. To evaluate the impact of probiotics intervention on gut microbiome (GM) composition and functions characterized by shotgun metagenomic sequencing of stool.
  4. To explore potential underlying mechanisms of Bifidobacterium-based probiotics on lowering BP by assessing serum proinflammatory and oxidative stress markers and circulating GM-derived metabolites, including SCFAs and GABA.

Additionally, the investigators will conduct sex-stratified analysis to explore potential sex differences in BP lowering response to the intervention since sex-linked differences in the initiation and progression of hypertension pathology are well-established, and the investigators recently reported that association between GM and hypertension is also sex-linked.

Conditions
Hypertension
Being tested
Bifidobacterium probiotics supplementation
Keywords
hypertension, Bifidobacterium, probiotics
Medical subject headings
Hypertension

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Bifidobacterium probiotics supplementationBiological

    The 12-week research period consists of one prescreening and baseline visit (week -1) and three follow-up visits (week 4 (±7days), week 8 (±7days) and week 12 (±7days)). The participants will be instructed to fast overnight before their visits in the mornings of week -1 and week 12.

    The measurements will include documentation of personal and demographic information; three consecutive clinic BP readings; 24-hour ambulatory BP monitoring; a 3-day diet diary to monitor consistency of dietary intake; collection of fecal samples and blood samples for analysis of GM composition and biomarkers, respectively at baseline, and week 8 and 12.

    Only participants who are able to provide all the required data and samples within 7 days after the prescreening and baseline visit (week -1) will be eligible to receive the Bifidobacterium supplementation with 20 billion cfu once a day for 12 weeks. They will be instructed to mix the probiotics with water and consume with their dinner.

Study groups in NCT07206303
Study groupRoleWhat they receive
30 recruited participants receiving commercially available probiotics supplementsExperimental30 community-dwelling, middle-aged Hong Kong Chinese (15 men and 15 women) with hypertension according to ACC/AHA guidelines (SBP ≥130 mm Hg) who are not taking antihypertensive agents and are free of symptomatic cardiovascular or cerebrovascular diseases will be recruited in this study. Participants will be recruited via our outreach promotion program or social media and recruitment posters will be distributed physically or posted online.
Receives: Biological: Bifidobacterium probiotics supplementation

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Mean seated clinic systolic blood pressure (SBP)

    Three consecutive BP measurements will be assessed using an automatic BP monitor, Microlife BP A200 AFIB (Microlife, Taiwan). Prior to taking BP measurements, participants will be instructed to sit and rest for at least five minutes. Participants will be advised to maintain an upright posture, with their arms positioned at heart level and palms facing upwards. Additionally, they will be advised to refrain from speaking during process. The average of three BP measurements will be taken to minimize random error.

    Measured: During clinical visits at: - Baseline (a week prior to treatment), - Week 4, 8 of treatment - Week 12 of treatment (end of treatment)

Secondary outcomes (6)

  1. Mean seated clinic diastolic blood pressure (DBP)

    Three consecutive BP measurements will be assessed using an automatic BP monitor, Microlife BP A200 AFIB (Microlife, Taiwan). Prior to taking BP measurements, participants will be instructed to sit and rest for at least five minutes. Participants will be advised to maintain an upright posture, with their arms positioned at heart level and palms facing upwards. Additionally, they will be advised to refrain from speaking during process. The average of three BP measurements will be taken to minimize random error.

    Measured: During clinical visits at: - Baseline (a week prior to treatment), - Week 4, 8 of treatment - Week 12 of treatment (end of treatment)

  2. Mean 24-hour ambulatory SBP

    A calibrated ambulatory BP monitoring device, TM-2441 (A\&D Medical, Japan) will be fitted onto the participants, with the BP cuff placed on their non-dominant arm to record the 24-hour ambulatory BP. The BP will be measured every 30 minutes from 6 am to 10 pm and then every 60 minutes from 10 pm to 6 am.

    Measured: During clinical visits at: - Baseline (a week prior to treatment), - Week 12 of treatment (end of treatment)

  3. Gut microbiome composition and functions

    Stool GM sequencing will be performed to compare GM abundance before and after probiotics intervention. This will enable metagenomic assembly community profiling and functional profiling, while facilitating the identification of presented taxa, their abundance, biochemical potential, and other relevant information. Other GM species that may be associated with hypertension could also be identified and provide valuable insights for the development of future GM-based intervention strategies. A set of OMNIgene-OMR205 kits (DNA Genotek, Canada) will be utilized for the collection and stabilization of gut microbial DNA and RNA, facilitating the profiling of gut microbiomes. We will also inquire about the participants' bowel habit concurrently, utilizing the Bristol Stool Chart as reference.

    Measured: During clinical visits at: - Baseline (a week prior to treatment), - Week 8 of treatment, - Week 12 of treatment (end of treatment)

  4. Plasma levels of gut microbiome-derived metabolites, short-chain fatty acids (SCFA) and gamma amino butyric acids (GABA)

    The level of SCFAs in blood sample will be detected by a two-steps analysis: the blood sample will be first derivatized by 1-propanol/pyridine (3:2, v: v) and propyl chloroformate followed by the quantification using 7890B gas chromatography-mass spectrometry after centrifugation of blood.

    Measured: During clinical visits at: - Baseline (a week prior to treatment), - Week 8 of treatment, - Week 12 of treatment (end of treatment)

  5. Serum levels of proinflammatory and oxidative stress markers

    Various inflammatory markers, including IL-1, IL-6, IL-8, TNF-α, IL-10 will be assessed using LEGENDplex™ 13-plex pro-inflammatory cytokine panel (BioLegend Inc., USA). Damages caused by radicals or excessive oxidants will be measured in the blood. DNA/RNA damage will be assessed by 8-Hydroxygaunaosine (8-OHG) or detecting the general DNA damage via comet assay. Lipid damage will be assessed by measuring malondialdehyde (MDA) levels and protein modification will be assessed by measuring the levels of advanced glycation end products (AGE).

    A portion of every blood sample will also be collected and preserved in a PAXgene Blood RNA tube manufactured by QIAGEN in Germany. This tube enables the extraction and purification of intracellular RNA for subsequent molecular diagnostic testing.

    Measured: During clinical visits at: - Baseline (a week prior to treatment), - Week 8 of treatment, - Week 12 of treatment (end of treatment)

  6. Sex differences in BP reduction after the intervention

    Measured: Demographics to be collected during baseline visit.

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted3 Oct 2025
  2. Study startNov 2026 (estimated)
  3. Primary completionNov 2027 (estimated)
  4. Study completionNov 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 1
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
30 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07206303
Sponsor's protocol ID
GL202401
Status last verified
Aug 2026
First submitted
25 Sep 2025
Last updated
31 Aug 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Chumpitazi BP, Self MM, Czyzewski DI, Cejka S, Swank PR, Shulman RJ. Bristol Stool Form Scale reliability and agreement decreases when determining Rome III stool form designations. Neurogastroenterol Motil. 2016 Mar;28(3):443-8. doi: 10.1111/nmo.12738. Epub 2015 Dec 21.

    PubMed 26690980

  • Kolodziejczyk AA, Zheng D, Elinav E. Diet-microbiota interactions and personalized nutrition. Nat Rev Microbiol. 2019 Dec;17(12):742-753. doi: 10.1038/s41579-019-0256-8. Epub 2019 Sep 20.

    PubMed 31541197

  • Azzi A. Oxidative Stress: What Is It? Can It Be Measured? Where Is It Located? Can It Be Good or Bad? Can It Be Prevented? Can It Be Cured? Antioxidants (Basel). 2022 Jul 23;11(8):1431. doi: 10.3390/antiox11081431.

    PubMed 35892633

  • Okita Y, Nakamura H, Kouda K, Takahashi I, Takaoka T, Kimura M, Sugiura T. Effects of vegetable containing gamma-aminobutyric acid on the cardiac autonomic nervous system in healthy young people. J Physiol Anthropol. 2009;28(3):101-7. doi: 10.2114/jpa2.28.101.

    PubMed 19483370

  • Hayakawa K, Kimura M, Kamata K. Mechanism underlying gamma-aminobutyric acid-induced antihypertensive effect in spontaneously hypertensive rats. Eur J Pharmacol. 2002 Mar 1;438(1-2):107-13. doi: 10.1016/s0014-2999(02)01294-3.

    PubMed 11906718

  • Verhaar BJH, Prodan A, Nieuwdorp M, Muller M. Gut Microbiota in Hypertension and Atherosclerosis: A Review. Nutrients. 2020 Sep 29;12(10):2982. doi: 10.3390/nu12102982.

    PubMed 33003455

  • Zheng X, Qiu Y, Zhong W, Baxter S, Su M, Li Q, Xie G, Ore BM, Qiao S, Spencer MD, Zeisel SH, Zhou Z, Zhao A, Jia W. A targeted metabolomic protocol for short-chain fatty acids and branched-chain amino acids. Metabolomics. 2013 Aug 1;9(4):818-827. doi: 10.1007/s11306-013-0500-6.

    PubMed 23997757

  • Virwani PD, Qian G, Hsu MSS, Pijarnvanit TKKTS, Cheung CN, Chow YH, Tang LK, Tse YH, Xian JW, Lam SS, Lee CPI, Lo CCW, Liu RKC, Ho TL, Chow BY, Leung KS, Tsang HW, Lo EKK, Tung KTS, Chung SK, Yuen MF, Leung SY, Ip P, Hung IF, Louie JCY, El-Nezami H, Ho JWK, Lau KK. Sex Differences in Association Between Gut Microbiome and Essential Hypertension Based on Ambulatory Blood Pressure Monitoring. Hypertension. 2023 Jun;80(6):1331-1342. doi: 10.1161/HYPERTENSIONAHA.122.20752. Epub 2023 Apr 19.

    PubMed 37073724

  • Gerdts E, Sudano I, Brouwers S, Borghi C, Bruno RM, Ceconi C, Cornelissen V, Dievart F, Ferrini M, Kahan T, Lochen ML, Maas AHEM, Mahfoud F, Mihailidou AS, Moholdt T, Parati G, de Simone G. Sex differences in arterial hypertension. Eur Heart J. 2022 Dec 7;43(46):4777-4788. doi: 10.1093/eurheartj/ehac470.

    PubMed 36136303

  • Lau RI, Su Q, Lau ISF, Ching JYL, Wong MCS, Lau LHS, Tun HM, Mok CKP, Chau SWH, Tse YK, Cheung CP, Li MKT, Yeung GTY, Cheong PK, Chan FKL, Ng SC. A synbiotic preparation (SIM01) for post-acute COVID-19 syndrome in Hong Kong (RECOVERY): a randomised, double-blind, placebo-controlled trial. Lancet Infect Dis. 2024 Mar;24(3):256-265. doi: 10.1016/S1473-3099(23)00685-0. Epub 2023 Dec 7.

    PubMed 38071990

  • Su Q, Liu Q, Zhang L, Xu Z, Liu C, Lu W, Ching JY, Li A, Mak JWY, Lui GCY, Ng SSS, Chow KM, Hui DS, Chan PK, Chan FKL, Ng SC. Antibiotics and probiotics impact gut antimicrobial resistance gene reservoir in COVID-19 patients. Gut Microbes. 2022 Jan-Dec;14(1):2128603. doi: 10.1080/19490976.2022.2128603.

    PubMed 36201636

  • Zhang L, Xu Z, Mak JWY, Chow KM, Lui G, Li TCM, Wong CK, Chan PKS, Ching JYL, Fujiwara Y, Chan FKL, Ng SC. Gut microbiota-derived synbiotic formula (SIM01) as a novel adjuvant therapy for COVID-19: An open-label pilot study. J Gastroenterol Hepatol. 2022 May;37(5):823-831. doi: 10.1111/jgh.15796. Epub 2022 Mar 2.

    PubMed 35170078

  • Chang BJ, Park SU, Jang YS, Ko SH, Joo NM, Kim SI, Kim CH, Chang DK. Effect of functional yogurt NY-YP901 in improving the trait of metabolic syndrome. Eur J Clin Nutr. 2011 Nov;65(11):1250-5. doi: 10.1038/ejcn.2011.115. Epub 2011 Jun 22.

    PubMed 21697819

  • Savard P, Lamarche B, Paradis ME, Thiboutot H, Laurin E, Roy D. Impact of Bifidobacterium animalis subsp. lactis BB-12 and, Lactobacillus acidophilus LA-5-containing yoghurt, on fecal bacterial counts of healthy adults. Int J Food Microbiol. 2011 Sep 1;149(1):50-7. doi: 10.1016/j.ijfoodmicro.2010.12.026. Epub 2011 Jan 15.

    PubMed 21296446

  • Agerholm-Larsen L, Raben A, Haulrik N, Hansen AS, Manders M, Astrup A. Effect of 8 week intake of probiotic milk products on risk factors for cardiovascular diseases. Eur J Clin Nutr. 2000 Apr;54(4):288-97. doi: 10.1038/sj.ejcn.1600937.

    PubMed 10745279

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing Bifidobacterium probiotics supplementation in people with Hypertension, run by The University of Hong Kong at 1 site in Hong Kong.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 31 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Hong Kong. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Gary Kui-Kai Lau (+852 22554249, gkklau@hku.hk), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Mean seated clinic systolic blood pressure (SBP) (time frame: During clinical visits at: - Baseline (a week prior to treatment), - Week 4, 8 of treatment - Week 12 of treatment (end of treatment)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07206303, which also lists 45 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 31 Aug 2026.

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