HEALTHPLAN MAGAZINE

High blood pressure, known as hypertension, is a global health issue impacting approximately 1.28 billion individuals aged 30 and above worldwide, according to the World Health Organisation (WHO). What makes this condition particularly insidious is that nearly half of those affected are oblivious to their hypertensive state since it typically remains asymptomatic unless blood pressure reaches exceptionally elevated levels.

In the United States alone, nearly half of all adults (48.1 percent) either have hypertension or are taking medication to manage it.

Hypertension significantly elevates the risk of severe health complications, including heart failure, heart attacks, aneurysms, kidney failure, strokes, amputations, and hypertensive retinopathies that can lead to blindness.

However, there are strategies to mitigate this risk, such as quitting smoking, moderating alcohol consumption, maintaining a healthy weight, and adopting a nutritious diet.

Research has suggested that a healthy diet, like the Mediterranean diet, can have a positive impact on the gut microbiome. This diet may enhance the population of probiotics, beneficial bacteria in the gut.

Now, a study conducted on mice has pinpointed two specific probiotics, Bifidobacterium and Lactobacillus, that appear to contribute to reducing blood pressure.

This study, led by researchers from the City University of Hong Kong and Inner Mongolia Agricultural University, is featured in the journal mSystems, published by the American Society for Microbiology.

Understanding the Role of Gut Bacteria in Blood Pressure Studies have demonstrated a connection between an imbalance in gut bacteria and hypertension in both animals and humans. Bacterial metabolism can influence the immune system, leading to inflammation and endothelial dysfunction, all of which impact blood pressure regulation.

Certain bacteria seem to have a favourable effect on blood pressure. Several studies have found that Lactobacillus spp. and Bifidobacterium spp., both found in dairy products, can lower blood pressure.

In this latest study, researchers explored the impact of two specific species, Bifidobacterium lactis M8 and Lactobacillus rhamnosus M9, on mice that developed hypertension after consuming water with 15 percent fructose instead of plain water.

During the 16-week trial, the mice were divided into four groups. One group received fructose water and intragastric saline, the second group received fructose water and B. lactis, the third group received fructose water and L. rhamnosus, and the control group had only plain water. The probiotics were administered via intragastric saline.

In the hypertensive mice given probiotics, their blood pressure significantly decreased over the course of the study, returning to the same level as the control group. Meanwhile, the fructose-fed mice not treated with probiotics continued to have elevated blood pressure.

Dr. Cheng-Han Chen, a board-certified interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center in Laguna Hills, who was not involved in the study, commented on the findings, stating that the study "used a specific 'high-fructose' mouse model of hypertension, and showed that the probiotics B. lactis M8 and L. rhamnosus M9 led to decreased blood pressure in these mice."

Probiotics: Balancing the Gut Microbiome

In addition to lowering blood pressure, the probiotics also seemed to induce changes in the composition of the mice's gut microbiome.

"The blood pressure reducing effect appears to be due to these probiotics adjusting the balance of the gut microbiome, specifically by increasing the levels of bacteria associated with lower blood pressure (Lawsonia and Pyrolobus), and decreasing the levels of bacteria associated with higher blood pressure (Alistipes and Alloprevotella)," explained Dr. Cheng-Han Chen.

Prof. Jun Li, an assistant professor in bioinformatics at the City University of Hong Kong, and Prof. Zhihong Sun, a microbiologist at Inner Mongolia Agricultural University, lead authors of the study, provided insights into how the alteration of gut bacteria could have this effect:

"We believe that the primary reason these probiotics, B. lactis M8 and L. rhamnosus M9, influence blood pressure in mice is closely tied to the regulation of the metabolic activities of the host. The blood pressure reduction observed was linked with an increase in Lawsonia and Pyrolobus and a decrease in Alistipes and Alloprevotella.

"Both strains regulated metabolic pathways including vascular smooth muscle contraction, serotonergic synapse, and cholinergic synapse. This study sheds light on the intricate ways through which gut microbiota impacts the overall health of the host," they added.

Could These Findings Apply to Humans?

"It is far too soon to know whether this data is more broadly applicable to people. The next stage of this research will be to test and replicate these findings in humans. A significant focus will be to study the amount and duration of probiotic therapy that will demonstrate a therapeutic effect," emphasised Dr. Cheng-Han Chen.

Professors Li and Sun are currently conducting further research in this domain, suggesting that a daily probiotic intake for people could range between 30-50 billion for a duration of three months. However, they also caution that the composition of gut microbiota can vary among individuals due to factors such as age and gender, which can influence the efficacy of probiotics. Therefore, determining the ideal dosage and duration necessitates further validation supported by clinical research.

Considering Probiotics in Your Diet

Although this study does not conclusively establish that probiotics reduce blood pressure, the evidence for their health benefits continues to grow. A 2013 review of studies found that probiotics can improve intestinal health and be beneficial in treating conditions such as lactose intolerance, antibiotic-associated diarrhoea, infectious diarrhoea, and allergies.

Another review from 2017 highlighted that the consumption of Lactobacillus can significantly reduce total blood cholesterol.

Probiotics can be consumed either as supplements or as part of a well-balanced diet. Dr. Chen recommends obtaining probiotics through natural foods, as they provide a more comprehensive array of nutrients. Nonetheless, Professors Li and Sun suggest considering probiotic powders or capsules with robust activity, adequate quantity, and diverse strains to ensure a consistent supply. It's important to consult a healthcare professional, especially for individuals with compromised immune systems, before taking probiotic supplements.

For most individuals, maintaining a balanced, healthful diet rich in fresh fruits and vegetables, yoghurt, cheese, and fermented foods is beneficial. Dr. Chen advises that people adhere to a well-rounded and diverse diet that includes probiotic- and prebiotic-containing foods.

In summary, while this study indicates the potential of specific probiotic strains in reducing blood pressure, it's crucial to consider the current limitations, such as the focus on mice and the need for further human trials. High blood pressure remains a prevalent concern, and a healthful lifestyle, including dietary choices, can play a significant role in its management. Consulting with a healthcare professional is advisable to make informed decisions about potential treatments or dietary adjustments.

Source: Medical News Today