Researchers tested whether yogurt and probiotics could help protect bones and hearts in animals with chronic kidney disease. They found that yogurt enriched with specific probiotics improved bone strength, while plain yogurt had no effect. Surprisingly, taking probiotics alone actually seemed to harm heart function. This early-stage research suggests that the combination of yogurt and probiotics might be better than either one alone, but more studies in humans are needed before making any recommendations.

The Quick Take

  • What they studied: Whether regular yogurt, yogurt with added probiotics, or probiotics alone could improve bone strength and heart health in animals with kidney disease
  • Who participated: 32 male laboratory rats divided into 4 groups: one group with kidney disease, and three groups with kidney disease that received different yogurt or probiotic treatments
  • Key finding: Yogurt enriched with Lactobacillus acidophilus probiotics improved bone strength measurements by about 2-4%, while probiotics alone actually worsened heart electrical activity and caused the heart to enlarge
  • What it means for you: This suggests that probiotic-enriched yogurt might help protect bones in people with kidney disease, but taking probiotics as a supplement alone could be harmful. However, this is early research in animals, so don’t change your diet based on this study alone—talk to your doctor first

The Research Details

Scientists used laboratory rats to model chronic kidney disease by surgically removing part of their kidneys. They then divided the sick rats into three treatment groups: one received regular yogurt, one received yogurt with added probiotics (a specific type called Lactobacillus acidophilus), and one received just the probiotic supplement. A fourth group had kidney disease but received no treatment, serving as a comparison.

The researchers measured multiple things over the study period: bone strength using special machines that bent the bones until they broke, heart function using electrocardiograms (machines that record the heart’s electrical signals), heart size and structure under a microscope, and various blood markers related to inflammation and stress in the body.

This type of study is called a controlled animal experiment because the researchers could carefully control what each group received and measure the effects precisely.

Animal studies like this one are important stepping stones before testing treatments in humans. They help researchers understand how different substances affect the body and identify which approaches are worth studying further. Since kidney disease patients often develop weak bones and heart problems, finding ways to prevent these complications could significantly improve their quality of life.

This study was published in a reputable nutrition journal and used careful scientific methods with controlled groups. However, it’s important to know that results in rats don’t always translate directly to humans—our bodies are more complex. The study was relatively small (32 animals total), which means the findings need to be confirmed in larger studies. The researchers measured many different outcomes, which is good for understanding the full picture but also increases the chance of finding results by coincidence.

What the Results Show

The most important finding was that yogurt enriched with probiotics significantly improved bone strength. Specifically, the bones of rats receiving probiotic-enriched yogurt were stronger and could withstand more force before breaking compared to rats with untreated kidney disease. The improvements were modest but measurable—about 2-4% stronger in several measurements.

Regular yogurt without added probiotics did not improve bone strength. The bones of rats eating regular yogurt were similar in strength to the untreated kidney disease group.

Surprisingly, probiotics given alone (without yogurt) actually had negative effects on the heart. Rats receiving only the probiotic supplement showed signs of heart damage, including abnormal electrical activity and enlargement of the heart muscle. These changes suggest the heart was working harder than normal, which is concerning.

The probiotic-enriched yogurt group showed better heart function than the probiotic-only group, with more normal electrical patterns and less heart enlargement. This suggests that the yogurt itself may have protective effects that counteract some of the probiotic’s negative effects.

Researchers also measured inflammation and oxidative stress (cellular damage from harmful molecules) in the blood, but found no significant differences between groups. They measured a specific compound called p-cresyl sulfate that builds up in kidney disease patients and can cause problems, but again found no differences. This suggests that the improvements in bones and heart function may work through different mechanisms than reducing these particular markers.

This is described as the first study directly comparing these three approaches (regular yogurt, probiotic yogurt, and isolated probiotics) in kidney disease. Previous research has suggested that probiotics might help kidney disease patients, but this study provides important new information: the source and form of the probiotic matters significantly. The finding that probiotics alone can harm the heart is particularly important because it contradicts the assumption that probiotics are always beneficial.

This study was conducted in rats, not humans, so the results may not apply directly to people. The study was relatively short-term, so we don’t know if the benefits would continue or change over longer periods. The sample size was small (only 8 animals per group), which means the results need to be confirmed in larger studies. The researchers didn’t measure how much of the probiotic was actually absorbed or how it moved through the body. Additionally, they only tested one specific strain of probiotic, so results might differ with other types.

The Bottom Line

Based on this early research, probiotic-enriched yogurt appears promising for bone health in kidney disease (moderate confidence level—more human studies needed). Regular yogurt showed no benefit or harm (low confidence—more research needed). Taking probiotic supplements alone may be harmful and should be avoided without medical supervision (moderate confidence—concerning findings warrant caution). Anyone with kidney disease should discuss yogurt and probiotic use with their nephrologist (kidney specialist) before making changes.

This research is most relevant to people with chronic kidney disease who are looking for ways to protect their bones and heart. It’s also important for healthcare providers treating kidney disease patients. People without kidney disease should not assume these findings apply to them. Pregnant women, children, and people with compromised immune systems should be especially cautious about probiotic supplements and should consult their doctor.

This is animal research, so we don’t have data on how long it would take to see benefits in humans. If human studies confirm these findings, benefits would likely take weeks to months to become noticeable. Bone strength improvements typically develop gradually over time.

Want to Apply This Research?

  • Track daily yogurt consumption (type and amount) and any bone or joint symptoms (pain, weakness, or changes in mobility) to monitor personal response if you have kidney disease and your doctor approves yogurt consumption
  • If your doctor approves, try incorporating one serving of probiotic-enriched yogurt into your daily diet and track any changes in energy levels, digestion, or bone-related symptoms over 8-12 weeks
  • Create a weekly log noting yogurt type consumed, any digestive changes, energy levels, and bone/joint symptoms. Share this data with your healthcare provider at regular appointments to assess whether the yogurt is helping or causing any problems

This research was conducted in laboratory animals and has not been tested in humans. The findings do not constitute medical advice. People with chronic kidney disease should not change their diet or start taking probiotic supplements without consulting their nephrologist or healthcare provider first. Probiotics can interact with medications and may not be appropriate for everyone, especially those with weakened immune systems. This study suggests isolated probiotic supplements may be harmful in kidney disease, so medical supervision is essential before use. Always discuss any dietary changes or supplements with your healthcare team.