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

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:

• To investigate if oral administration of Bifidobacterium-based probiotic intervention will reduce clinic SBP and DBP from baseline to the end of treatment.
• 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.
• To evaluate the impact of probiotics intervention on gut microbiome (GM) composition and functions characterized by shotgun metagenomic sequencing of stool.
• 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.

Inclusion criteria

• 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.

Exclusion criteria

• 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, antibiotics, rifaximin, steroids, and antihypertensive agents within 4 weeks.
• 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 SIM01probiotics 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.