“Listen to your gut” is more than just a saying—it’s a key to better health. For patients with chronic kidney disease (CKD), gut health has become an increasingly important focus. Research continues to shed light on the intricate connection between the gut and kidneys, known as the gut-kidney axis. In this article, we’ll explore the role of gut health in kidney disease management, including the impact of prebiotics, probiotics, postbiotics, and synbiotics. We’ll also discuss the benefits of specific foods and supplements, like Renadyl™, that support both gut and kidney health. Lastly, we will answer the question many kidney patients have – can probiotics lower creatinine?
This blog post is sponsored by Renadyl™ and contains sponsored links marked with an asterisk (*). If you click and make a purchase, I may earn a commission at no additional cost to you. All opinions shared are my own.
A Quick Reminder: Always consult with your healthcare provider before starting any new supplements, especially if you have a medical condition or are taking medications.
Table of Contents
The Importance of Gut Health
The gut, also known as the digestive system, wields significant influence over overall health. It affects everything from mental health to physical well-being.
The gut is home to a vast ecosystem of bacteria – both “good” and “bad”—approximately 39 trillion cells in total, which outnumber the human body’s cells by far.
Most of these bacteria live in the large intestine. (1)
Why Gut Health Matters
The gut plays a crucial role in breaking down nutrients from food, housing a significant portion of the immune system, and maintaining overall health. (2)
Gut health is particularly important for kidney patients, as it can impact kidney disease both directly and indirectly.
Gut health can also impact other health concerns such as diabetes, obesity, metabolic syndrome, and cardiovascular disease. (3)
The Gut-Kidney Axis
The gut-kidney axis describes the dynamic relationship between gut bacteria, the intestinal barrier, and the kidneys.
This connection is bidirectional: while gut health can influence kidney function, kidney issues can also disrupt gut health.
Maintaining a healthy gut can help maintain healthy kidneys or slow the progression of chronic kidney disease (CKD).
Video about Probiotics & Kidney Health
Watch Michele from Plant-Based Kidneys talk more about probiotics in this video below:
Dysbiosis in Kidney Patients
CKD patients often experience dysbiosis. This is otherwise known as an imbalance of “good” versus “bad” gut bacteria.
Research shows that CKD patients have lower levels of beneficial bacteria like Lactobacillus and Bifidobacterium. (4)
This can result in increased creation and amounts of compounds that can be harmful like creatinine, uric acid, blood urea nitrogen (BUN) and others.
Causes of Dysbiosis
Factors like dietary restrictions, slowed digestion, antibiotics, iron supplements, and phosphate binders—common in CKD treatment—can contribute to dysbiosis.
While these interventions are vital for kidney health, addressing their impact on gut health is essential for holistic care.
Protein Breakdown and Toxin Production
Certain gut bacteria, such as Clostridium and Bacteroides, are responsible for breaking down undigested protein.
However, this process also produces;
- Ammonia
- Amines
- Thiols
- Indoles
- Phenols
These are also known as endotoxins.
Some of these endotoxins are pro-inflammatory toxins that can damage the kidneys. (5)
Kidney patients tend to have higher levels of these bacteria.
Higher levels of these bacteria result in increased endotoxin production and kidney damage. (6)
Uremic Toxins and Kidney Health
Uremic toxins are a hallmark of chronic kidney disease and include substances such as:
- Indoxyl sulfate
- P-cresyl sulfate
- Hippuric acid
- Trimethylamine N-oxide (TMAO)
- Asymmetric dimethylarginine (ADMA)
These toxins tend to build up in the body and contribute to increased inflammation and increased stress on the kidneys. (7)
This can fast-track CKD progression and raise the risk of other health issues including cardiovascular disease.
Butyrate and Kidney Health
Butyrate is a type of short-chain fatty acid (SCFA) that is produced in the gut and is beneficial for gut and general health.
Butyrate supports healthy cells, protects the gut barrier, reduces inflammation, and boosts the immune system. (8)
Kidney patients often have lower levels of butyrate due to low levels of Lactobacillus bacteria, which can contribute to worsened kidney function. (9)
Increasing healthy Lactobacillus bacteria can help restore butyrate levels.
There are other short chain fatty acids that are produced in the gut as well that are helpful for good health.
Lactobacillus bacteria can also help boost production of those SCFAs.
Prebiotics: Feeding Good Bacteria
Prebiotics are non-digestible fibers that nourish beneficial gut bacteria.
Including prebiotics in your diet can lead to (10):
- improved calcium absorption
- a stronger gut barrier
- better immune function
Prebiotic-Rich Foods
Foods high in prebiotics include garlic, onions, asparagus, lentils, and oats.
Some of these foods were traditionally restricted in renal diets due to potassium or phosphorus content
However, updated dietary guidelines now emphasize personalized approaches based on individual health needs.
Below is a table of prebiotic-rich food for reference (11):
Vegetables | Garlic, onion, leek, shallots, spring onion, asparagus, beetroot, fennel, Jerusalem artichokes, green peas, snow peas, corn, savoy cabbage, dandelion greens, jicama, yacon root, elephant yam |
Fruit | Custard apples, nectarines, white peaches, persimmon, avocado, tamarillo, watermelon, rambutan, grapefruit, pomegranate, dates, figs |
Legumes | Soybeans, lentils, chickpeas, kidney beans, baked beans |
Grains | Wheat bran, wheat bread, barley, rye, pasta, gnocchi, couscous, oats |
Nuts | Cashews, pistachios |
Other | Cocoa, seaweed |
Prebiotics in Renadyl™
Renadyl™ contains fructo-oligosaccharides and xylo-oligosaccharide, two prebiotics that support gut health.
Fructo-oligosaccharides help boost production of short chain fatty acids.
Xylo-oligosaccharide supports the immune system, acts as an antioxidant, and even protects against tumors (12).
Probiotics: The Power of Good Bacteria
Probiotics are the living, functioning bacteria in the gut. These are our “microfriends” that do the work that support our health.
Probiotics are found in both foods and supplements.
Both options can be very useful for kidney patients to help ensure a thriving bacteria colony in the gut.
And while including plenty of prebiotics is a very important part of a healthy gut, it’s just as important to include probiotics.
Probiotics Reduce Uremic Toxins
Some research supports probiotic use for kidney patients.
A meta-analysis published in 2022 looked at ten trials including over 500 patients with diabetic kidney disease to determine the impact of probiotics (13).
They found that certain specific probiotics could help lower:
- serum creatinine
- blood urea nitrogen (BUN)
- fasting blood glucose
- insulin levels
- hemoglobin A1c (HgbA1c)
- total cholesterol
- Cystatin-C (Cys-c)
Specifically, increasing the use of certain Lactobacillus and Bifidobacterium probiotics may support reducing uremic toxins and inflammatory markers in kidney patients (14).
Can Probiotics Lower Creatinine and BUN?
To answer the question that many kidney patients have- yes, certain probiotics have been shown to reduce creatinine and blood urea nitrogen (BUN).
Probiotic-Rich Foods
Foods with probiotics usually have the Lactobacillus and Streptococcus bacterias. (15)
As discussed earlier, these bacterias are good bacteria for the gut. Therefore, including foods with probiotics helps to nourish a healthy gut.
Here is a table of sources of probiotics found in food.
Dairy | Yogurt, kefir, buttermilk, aged cheeses |
Plants | Sauerkraut, kimchi, miso, tempeh, pickles, kombucha, natto |
Grains | Sourdough bread |
It’s important to read the labels when looking for foods with probiotics. It should say something like “contains live/active cultures.”
Because heat can kill the probiotics, these foods are also typically refrigerated.
Dietary Restrictions with Probiotics-Rich Foods
Similar to prebiotic-rich foods, some probiotic-rich foods have traditionally been limited in renal diets.
Yogurt, for example, is known to be a good source of both potassium and phosphorus. It can also be high in protein.
Many fermented foods are also typically high in sodium. A quarter cup of sauerkraut has approximately 235 milligrams of sodium (16).
This is equivalent to just over 10% of the recommended sodium guidelines for kidney patients.
While there are no official guidelines for how often probiotic-rich foods should be included, just one or two servings a day may be helpful in supporting your gut.
Delivering Probiotics Safely to the Gut
For probiotics to be effective, they need to reach the large intestine. The large intestine, aka colon, houses the most probiotics in the digestive system (1).
This means traveling through the mouth, esophagus. and stomach.
To do this, they must be able to bypass digestive enzymes, stomach acid, pancreatic juices and bile acids the body uses to effectively break down foods and nutrients (17).
Postbiotics: The Unsung Heroes
Postbiotics are beneficial compounds produced by healthy gut bacteria.
They include short-chain fatty acids (SCFAs), vitamins (like B12 and K), and enzymes, among others.
These compounds play vital roles in supporting the immune system, reducing inflammation, and protecting the gut barrier.
Synbiotics: A Simplified Gut Health Option
Synbiotics are a combination of prebiotics and probiotics that work together to provide a benefit to the gut (18).
Examples of Synbiotics in Food
Here are some examples of foods that provide both prebiotics and probiotics:
- Miso soup with asparagus and leeks
- Yogurt with dried fruit & cashews
- Overnight oats with rolled oats and yogurt or kefir
- Chickpea salad sandwich on whole wheat bread with pickled onions
- Bean chili with plain yogurt
- Tempeh stir-fry with kimchi
Synbiotic Supplements
Synbiotics combine prebiotics and probiotics to offer enhanced gut health benefits.
While many synbiotic supplements are available, finding one tailored to specific health concerns, such as kidney health, can be challenging.
RenadylTM is an example of a synbiotic supplement that incorporates prebiotics like inulin and probiotics like Lactobacillus to support gut balance.
Always consult with your healthcare provider when considering synbiotic supplements to ensure they align with your health needs.
Learn more about Renadyl here* and use code KIDNEY10 at checkout for a new customer discount.
The Path to Better Gut and Kidney Health
Since we have gone through a quick overview about gut health, now is time to act.
This next section dives into what kidney patients can do to support their kidney health by fostering a healthy gut.
Probiotic Supplements
For kidney patients, a high-quality probiotic supplement can help balance gut bacteria and support overall health.
As answered above, some specific probiotics can lower creatinine levels, one of the most identifiable toxins known to kidney patients.
Probiotics can be consumed in many forms; liquids, powder, capsules, tablets, and suppositories.
The different forms have ways to help protect the probiotics to reach the gut (19).
It’s important to note that only taking probiotics while disregarding healthy dietary changes may not result in any benefit for kidney patients (20).
RenadylTM
RenadylTM, for instance, delivers 45 billion CFU (colony forming units) per capsule and includes strains specifically formulated to reduce uremic toxins, creatinine and other harmful compounds.
Its acid-resistant capsules ensure probiotics reach the gut, where they can support digestive and kidney health.
While other probiotic options exist, RenadylTM is one of the only few designed with kidney health in mind.
In fact, RenadylTM is the #1 nephologist recommended probiotic.
Probiotics In RenadylTM
Their probiotic formulation of Lactobacillus thermophilus (KB19), Lactobacillus acidophilus (KB27) and Bifidobacterium longum (KB31) help metabolize urea, uric acid, and creatinine.
To protect the delivery of these healthy bacteria to the gut, Renadyl is housed in acid-resistant capsules.
In addition, Renadyl contains helpful prebiotics fructo-oligosaccharides and xylo-oligosaccharide.
Support your gut and kidney health today with Renadyl. Use code KIDNEY10 at checkout for a new customer discount and start your journey to better health.
Side Effects with Probiotic Supplements
While there is a risk of some side effects with probiotics, they are usually minor and disappear after a few weeks of consistent probiotic adherence.
Studies with Renadyl found no significant difference in side effects between Renadyl and a placebo (21, 22).
Minor side effects reported included some gas and bloating that disappeared after about a week with continued supplementation.
Supplements or Diet: Which is Best?
One of the common questions kidney patients have is, “Can’t I just take a probiotic like RenadylTM and not deal with my diet?”
Unfortunately, that is not the case.
While supplements can be a very important part for a kidney patient, taking it without diet changes will not produce beneficial results.
However, taking a supplement like Renadyl while also eating more prebiotic- and probiotic-rich foods can be an incredibly powerful way to support your kidney health.
Many people find that taking a supplement can help motivate them to make dietary changes.
If that is the case for you, I encourage you to try a synbiotic like Renadyl for 90 days.
Learn more about Renadyl here* and use code KIDNEY10 at checkout for a new customer discount.
Summary
The gut-kidney axis highlights the important role gut health plays in overall kidney function.
For kidney patients, maintaining a balanced gut microbiome can help reduce inflammation, lower uremic toxin levels, and support better digestion and immunity.
Prebiotics, probiotics, and synbiotics work together to nourish beneficial gut bacteria, strengthening this connection and promoting a healthier body overall.
Probiotics, in particular, have been found to lower serum creatinine levels, a concern many kidney patients have when it comes to protecting kidney function.
Dietary adjustments, such as incorporating prebiotic- and probiotic-rich foods, are key steps in this process.
However, supplements like Renadyl can provide additional targeted support, especially for those with dietary restrictions or chronic conditions like CKD.
By combining a balanced diet with supplements that support gut health, kidney patients can take proactive steps toward improving their well-being.
Remember, gut health is more than just a trendy topic—it’s a cornerstone of managing kidney health effectively. With informed choices and a commitment to supporting your body’s natural processes, you can take meaningful strides toward better health.
Explore options like Renadyl* and consider discussing these strategies with your healthcare provider to begin your journey to optimal wellness.
Addressing gut health is a promising strategy for CKD patients looking to improve their overall well-being.
Through a balanced diet rich in prebiotics and probiotics, along with targeted supplements like Renadyl™, it’s possible to support both gut and kidney health.
Learn More About Renadyl™
To explore the benefits of Renadyl™ and receive a discount for first-time customers, visit Renadyl’s website* and use code KIDNEY10 at checkout.
Jen Hernandez is a registered dietitian and board-certified specialist in renal nutrition. She has nearly a decade of experience with kidney disease patients in all stages - from stage 1 through kidney transplant. Jen writes on the blog of Plant-Powered Kidneys to help reach and teach more kidney patients about how they can enjoy more foods in a plant-based diet while protecting kidney health.