The Gut Microbiome and High Blood Pressure – the bacterial connection!

Before plunging into today’s topic about the human microbiome, and some interesting research which suggests that a healthy microbiome has a role to play in helping maintain healthy blood pressure numbers, I thought I should back up for a minute and take a quick look at what we actually mean by the human microbiome.

The role of bacteria and their overall influence on our bodies is still a relatively new area of investigation, and certainly in the next few years more research will be directed at exploring just how key this really is in maintaining good health.

Indeed the microbiome itself has been referred to as “the Third Brain” because of its influence in the development and functioning of all systems, as well as organs, from our actual brain to our immune system. So this is certainly an area of scientific research to be keeping an eye on as time goes on.

What is the Human Microbiome?


With an understanding of the role of the microbiome under our belts, it is now time to address the connection between healthy gut flora and blood pressure regulation…

Gut Health and Blood Pressure

This is where things start to become interesting…

You see, some scientists, who have been doing research into the effects of microbes on body systems, have discovered that there may very well be a cause and effect relationship between the bacteria found in our guts and the way in which our kidneys are able to manage our blood pressure.

This research which is being conducted by Jennifer L. Pluznick (Assistant Professor of Physiology) and her team at the Johns Hopkins University School of Medicine, may in time offer an approach for those people who are trying to manage the most prevalent form of Hypertension;  the type of high blood pressure which seems to have no actual underlying cause.

Known as primary hypertension, it is by far the most common form of high blood pressure in North America today.  As it is so difficult to pinpoint a root cause for this type of high blood pressure, it has been quite difficult to treat effectively.

But this is where this new research offers hope…

Professor Plusnick’s work shows that a link between the gut and the kidneys could reveal a new cause of hypertension — and possibly, ways to prevent, or at least deal proactively with it.

What about the Kidneys?

Healthy functioning kidneys themselves play a key role in regulating blood pressure in several ways:

  1. they get rid of inflammation-causing waste/toxic material in the blood by filtering it out and eliminating it with the urine.
  2. they keep blood pressure in check by monitoring the volume of liquid in the body.  The kidneys are able to adjust this in order to maintain an optimal amount, so that neither too much pressure, nor too little pressure is applied on the blood vessel walls.  In other words, they the stabilize blood pressure.
  3. they monitor the amount of sodium in the body, since too much salt causes fluid retention which leads to high blood pressure.
  4. they trigger an enzyme called Renin which is responsible for a process leading to the constriction of blood vessels.

Unlocking the Connection between the two:

So now for the good part… The bacteria found in the gut is responsible for metabolizing food and in the process they cause the formation of molecules called ‘short chain fatty acids’ or SCFA for short. These SCFA then circulate throughout the blood system delivering energy to all the major organs, the kidneys included.

The Pluznick Team discovered that the kidneys contain cell receptors for short chain fatty acids which are specifically responsible for blood pressure regulation. They then focussed on two in particular – the Grp41 and Olfr78 receptors.  By investigating what these receptors were actually receiving, they determined – and this was previously unknown – that the these were receptors for the short chain fatty acids produced by the gut microbiome.

So, equipped with this information, the Team was able to complete a test on a mouse which resulted in the mouse’s blood pressure being lowered simply by injecting its bloodstream with short chain fatty acids.

Of further significance was the fact that whilst the Grp41 receptor led to decreased blood pressure, the Olfr78 receptor caused a raising of blood pressure.

This might sound contradictory at face value.  However, in actuality the sum effect of having these two receptors performing opposite functions on blood pressure is to allow a more gradual drop in blood pressure.  So, it is in effect providing a counterbalance to ensure blood pressure does not drop too suddenly, which in itself can be dangerous.

The neat thing about this research is that Pluznick and her team were not anticipating that the kidney receptors identified above would respond to short chain fatty acids from the gut the way they did.

And so the link between the kidneys and the digestive microbiome was thus established which now opens the way for further promising research.

Supporting the digestive microbiome

Clearly, given the importance of this link between the human biome, the kidneys and blood pressure, the obvious question now becomes:

How can we support the state of our digestive microbiome, so that it can continue to promote good health not only in those organs which deal specifically with blood pressure management, but also in the entire body – and thereby help us to stay disease-free as we age?

Consuming a diet rich in both Prebiotics and Probiotics is a good place to start.  Although these two sound similar, they are quite different in how they work!


Most of us have heard about probiotics because in recent years they have received a lot more attention, so I’ll start with them…

Probiotics are live bacteria caused by the natural fermentation process of such foods as yogurt, sauerkraut, kimchi or in fermented drinks like kefir and kombucha.

==▶︎ click here for my homemade Kombucha recipe ◀︎==


Probiotics also come in supplement form.  When we consume such foods, or ingest such supplements, we are allowing beneficial bacteria into our bodies which eventually end up in the colon where conditions allow the good bacteria to multiply.

The two most common forms of Probiotics are:

  • Lactobacillus – the most common probiotic found in yogurt and other fermented foods. It may help with people who can’t digest milk sugar (lactose), or in people suffering from diarrhea
  • Bifidobacterium – also found in some dairy products. It may ease symptoms of digestive tract conditions, such as irritable bowel syndrome (IBS). This group of probiotic bacteria is naturally present in the large intestine, where they fight harmful bacteria in the intestines, prevent constipation and give the immune system a boost.

Probiotics have been shown to have a positive effect on hypertension, as reported by Jing Sun, Ph.D., lead author and senior lecturer at the Griffith Health Institute and School of Medicine, Gold Coast, Queensland in Australia.  His team looked at a number of studies which focussed on the role of probiotics in maintaining healthy blood pressure.

As Dr Sun commented:

“The small collection of studies we looked at suggest regular consumption of probiotics can be part of a healthy lifestyle to help reduce high blood pressure, as well as maintain healthy blood pressure levels,” 


Attention amongst scientists is now turning increasingly to the important role Prebiotics can also play in maintaining a healthy gut microbiome.

What are prebiotics?  Well, prebiotic fibre is that part of certain plants which is basically non-digestible and which ends up in the colon where the warm environment is ideal for causing fermentation.  Examples of such indigestible fibre include parts of bananas, onions and garlic, Jerusalem artichoke and the peels of various fruits, like apples – and also many types of beans.

This fermentation process then provides sustenance to the beneficial bacteria living there and enables rapid multiplication of the bacterial colonies which in turn promote health by strengthening the body’s immune system and its ability to fight off diseases.

The advantages of prebiotics over probiotics lie in the fact that prebiotics are not susceptible to exposure to heat, stomach acid or time which can minimize the effectiveness of probiotics.  The latter are living organisms which are fragile and easily killed by the three factors mentioned above.

Also the fermentation process of prebiotics is the same for everyone.  By contrast, due to individual body differences, the exact amount of which probiotic will be of most benefit for a particular individual is mcuh harder to determine.

In short, it appears that the addition of both pro and prebiotics to one’s diet is highly recommendable.

Final Thoughts

“The biggest influence you can have on the state of your gut lining, and a healthy microbiome, is your diet — which you control.” 

(Jeannette Hyde, Nutritional Therapist BSc., a leading nutritional therapist and author of The Gut Makeover and The Gut Makeover Recipe Book)

There is a war raging every day in our guts between healthy and unhealthy bacteria.  If we know how to give our bodies the right ingredients needed to boost the healthy bacteria, and thereby promote a healthy digestive system, why wouldn’t we?

A healthy gut biome will benefit your body in many ways, including helping to build and maintain a strong immune system, keeping harmful inflammation at bay and maintaining stable blood glucose levels..  and now it seems it can help your kidneys to keep your blood pressure under control.

So, the advice above in the quote, I feel, couldn’t be more on point!!


  1. Catriona Darroch

    Thank you, very interesting and gives thought to further investigation.

    1. Nick (Post author)

      Many thanks to you for the positive feedback on the post, Catriona. I am always happy if my blogs can be a springboard for uncovering further insight and information on a given topic. All the best!