Kidney Coach

What does your gut health have to do with your kidneys?

MICROBIOME AND kidney and renal disease and function

If you’ve ever seen a naturopath, you probably noticed that we’re a bit obsessed with gut health. Over 2000 years ago Hippocrates, the father of medicine said, ‘All disease begins in the gut’ and with more and more research into the gut microbiome and its role in health and disease, it appears that he wasn’t far off!

Now, what actually is the gut microbiome?

Your gut microbiome is made up of the trillions of microorganisms and their genetic material that live in your intestinal tract. These include not only bacteria but fungi, parasites and viruses. 

 In fact, there are more bacterial cells in your body than human cells which means we are actually more bacteria than human!

Each person has an entirely unique network of microbes. Your gut begins to populate with bacteria while you are still in the womb, when you’re born there are many factors that influence the types of bacteria that will live and flourish in your gut. As you grow there continue to be many things that can shape the bacteria that live in your gut, like our environment, stressful events, illness, antibiotic use and lifestyle behaviours like diet and exercise. 

What is a ‘Healthy Gut’?

We all live our day-to-day lives in different environments with different combinations of habits and surroundings. Because of this, each of us has a gut microbiome that looks at least slightly different to that of our parents, siblings or overseas friends- your microbiome is like a bacterial fingerprint, specific to you. 

For this reason, and also because there is so much about our microbiota that we have yet to fully understand, it’s difficult to say exactly what makes up a healthy gut microbiome but we do know that there are certain bacteria that are more healthful and others that are linked to poor health and disease.

Functions of the gut microbiome

Your gut microbiome is responsible for a number of functions that are critical to our health and well-being including: 

  •     Regulate digestion and nutrition
  •     Mucosal function
  •     Immune system development and regulation
  •     Protect against pathogens
  •     Metabolic homeostasis
  •     Brain function- emotion, mood, cognition
  •     Synthesis of certain vitamins and amino acids

Now for the question I’m sure you’re wondering about:

What does your gut health have to do with your kidneys?

microbiome and Kidney disease and renal function

It is now well established that the gut microbiome is altered in kidney disease and that the resultant dysbiosis (imbalance of gut bacteria) contributes to the progression of CKD. 

There are a number of reasons why people with CKD have dysbiosis, some of these include dietary restrictions, low fibre intake, metabolic acidosis, slow gut transit, retention of uraemic toxins and use of medications that are detrimental to gut bacteria including antibiotics and phosphate binders. 

When in balance, the colonies of microorganisms that live in our gut tend to have a favourable effect on our bodies. When there is an imbalance, we may experience unwanted symptoms which affects our gut health. Dysbiosis has been identified as playing a possible role with a variety of health problems including:

  •     Inflammatory bowel disease
  •     Irritable bowel syndrome
  •     Obesity
  •     Metabolic syndrome
  •     Type 2 diabetes
  •     Eczema
  •     Autoimmune conditions

Work in the past few years has clearly shown that dysbiosis contributes to the progression of CKD which is due in part to the generation of excessive amounts of potentially toxic compounds while production of beneficial short chain fatty acids is reduced. 

Uraemic toxins come from the metabolism of partially digested protein by specific species within the microbiome, and these are known to promote CKD. These enteric toxins include protein bacterial metabolites such as urea, indoxyl sulfate and p-cresyl sulfate.

factors affectiong microbiome and kidney function

These uraemic toxins are absorbed into the bloodstream to be cleared by the kidneys, this puts further stress on the kidneys and when the kidneys aren’t functioning optimally, these uraemic toxins then build up in the bloodstream causing symptoms like nausea, itchy skin, loss of appetite, fatigue, high blood pressure, anaemia and heart disease and cause damage and scarring to the kidneys. 

Dysbiosis is also associated with increased intestinal permeability (or ‘leaky gut’), this allows small particles, like bacteria or small bits of food to escape into your bloodstream, where they are marked as intruders and trigger your immune system into action.

There is increasing evidence for ‘leaky gut’ as a factor in various diseases. Continuous immune activation and the inflammation that goes with it puts you at risk for a range of diseases and contributes to the progression of kidney disease.

leaky gut and kidney disease and renal function

Treatment of dysbiosis

When looking to improve the balance of bacteria in the gut, there are three primary ways to do this and that is with probiotics, prebiotics and through our diet.

Today I want to focus on probiotics.

What are probiotics?

The term probiotic (from the Greek for life) has had a number of different meanings over recent history. The current definition comes from the International Scientific Association of Probiotics and Prebiotics. They define probiotics as ‘live organisms that, when administered in adequate amounts, confer a health benefit to the host.’

Simply put, probiotics are either foods that naturally contain healthful bacteria or supplements containing live beneficial bacteria and/or yeasts that naturally live in the body and have been shown to have beneficial effects.

Probiotic Nomenclature

To better understand the upcoming discussion on probiotic strains, it’s important to first be clear on how bacteria are named. 

Genus is the first name of a bacterium (eg. Lactobacillus), it is somewhat general and refers to a grouping of organisms based on similar characteristics. 

Species is a bacterium’s second name (eg. rhamnosus). It’s a much narrower classification based on shared common features that distinguish them from other species within that genus.

Strain is an even more specific classification that divides members of the same species into subgroups based on one or more properties that these bacteria have that are distinct from other members of the species (eg. strain GG).

Within each species of bacteria there are multiple strains. Strains of bacteria within the same species can have significantly different actions, properties and characteristics, as many of these characteristics are strain-specific qualities. 

This also goes for probiotics as a whole, different probiotics have different actions, so you need to choose the correct probiotic (and even more specifically the correct strain) based on the action you are specifically looking for.

Actions of probiotics

Probiotics play a vital role within your gut. Some of the actions of probiotics include (but aren’t limited to):

  •     Improve immune system function
  •     Reduce inflammation
  •     Prevent and treat constipation and diarrhoea
  •     Prevent & treat gut infections
  •     Improve nutrient absorption
  •     Produce beneficial compounds eg. short chain fatty acids
  •     Repair and strengthen intestinal barrier
  •     Increase mucin (gut mucosal layer) production
  •     Improve mental health
  •     Help with weight loss

As you can see, that’s a long list of actions so it makes sense that no one probiotic can do it all. You need to pick the correct probiotic (species AND strain) to get the therapeutic effect you’re looking for. 

Studies looking at the benefits of probiotics in kidney disease have shown that specific probiotics (with or without prebiotics) can reduce levels of uraemic toxins (such as indoxyl sulfate and p-cresyl sulfate), lower inflammation and oxidative stress markers, decrease blood urea nitrogen, decrease uric acid, improve gastrointestinal symptoms, slow progression of kidney disease and improve quality of life. 

Researched probiotics in Kidney disease

Here is a list of probiotics that studies have shown to be of benefit in people with kidney disease. 

  •     Lactobacillus acidophilus KB27
  •     Bifidobacterium longum KB31
  •     Streptococcus thermophilus KB19
  •     Bifidobacterium KB35
  •     Lactobacillus rhamnosus CUL 63
  •     Lactobacillus casei CUL 06
  •     Lactobacillus plantarum CUL 66
  •     Lactobacillus fermentum CUL 67
  •     Lactobacillus acidophilus CUL 21 + CUL 60
  •     Bifidobacterium animalis spp. Lactis CUL 34
  •     Bifidobacterium breve CUL 74
  •     Bifidobacterium bifidum CUL 20
  •     Streptococcus thermophilus CUL 68
  •     Bifidobacterium bifidum A218
  •     Bifidobacterium longum A101
  •     Lactobacillus plantarum A87
  •     Lactobacillus casei Shirota

Choosing an effective probiotic

There are three key steps in choosing an effective probiotic preparation.

The first step is finding out the identity of the organism(s) in the preparation. It’s important to know not only the genus and species of the organism(s), but also the strain detail. Ideally, this information should be detailed on the label, but if it’s not, manufacturers should tell you this information upon request. 

The second step is working out whether there is any research conducted on the exact strains found in the supplement (this is where a good healthcare practitioner comes in handy!) and does it fit the purpose you need it for.

Thirdly, there should be adequate amounts of viable organisms contained in the product at the time of consumption- for most strains this is currently considered to be > 109 CFU of each organism per dose.

Final thoughts

Probiotics have many advantages and can provide a variety of different health benefits but if you are looking to use probiotics for a specific therapeutic effect then it’s important that you choose the strain that has proven benefits for that indication. 

As always, we recommend consulting your naturopath or healthcare practitioner before starting any new supplements.

I hope you’ve found this information helpful and now have a better understanding about the importance of the gut microbiome in all aspects of health and illness, including kidney disease. Makes sense now why Hippocrates said ‘All disease begins in the gut’ doesn’t it!

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