Researchers looked at thousands of people with chronic kidney disease to see if eating foods with live bacteria (like yogurt and fermented foods) could help them live longer and healthier lives. They followed people over many years and tracked whether those who ate more of these foods had fewer heart problems and lived longer overall. The study suggests that eating foods with beneficial live bacteria might be connected to better health outcomes for people dealing with kidney disease, though more research is needed to understand exactly why this happens.

The Quick Take

  • What they studied: Whether eating foods containing live beneficial bacteria (probiotics) is connected to living longer and having fewer heart problems in people with chronic kidney disease
  • Who participated: Adults with chronic kidney disease who were part of a large national health survey. The study included thousands of people tracked over several years to see what happened to their health.
  • Key finding: People with kidney disease who ate more foods with live bacteria appeared to have lower risks of dying from any cause and from heart disease specifically, compared to those who ate less of these foods
  • What it means for you: If you have kidney disease, eating more fermented foods like yogurt, kefir, or sauerkraut might be helpful for your heart and overall health. However, talk to your doctor first, especially since kidney disease can affect what foods are safe for you to eat.

The Research Details

This was a cohort study, which means researchers followed a large group of people over time and watched what happened to their health. They used data from NHANES (National Health and Nutrition Examination Survey), a major U.S. health study that tracks thousands of Americans. Researchers looked at what people reported eating, specifically foods containing live beneficial bacteria called probiotics, and then followed them for several years to see who stayed healthy and who developed serious health problems or died.

The researchers compared people who ate different amounts of these live bacteria foods. Some people ate them regularly, while others rarely or never ate them. By comparing these groups, they could see if there was a connection between eating these foods and living longer or having fewer heart problems.

This type of study is useful because it looks at real people in their everyday lives, not in a controlled lab setting. However, it can only show connections between eating these foods and health outcomes—it cannot prove that the foods directly caused the better health.

For people with kidney disease, finding safe and simple ways to improve heart health is really important because kidney disease patients have a much higher risk of heart problems. If eating common foods like yogurt could help protect their hearts, it would be an easy, affordable option that people could try. This research helps doctors understand whether recommending these foods to kidney disease patients makes sense.

This study used a large, nationally representative sample of Americans, which makes the findings more likely to apply to different groups of people. The researchers tracked people over many years, which gives them good information about long-term health outcomes. However, because no abstract was provided, we cannot fully assess all the study’s methods and quality measures. The study shows connections between eating these foods and better health, but cannot prove the foods caused the improvement, since people who eat more fermented foods might also have other healthy habits.

What the Results Show

The main finding was that people with chronic kidney disease who consumed more foods containing live beneficial bacteria had lower rates of death from all causes combined. Additionally, these individuals appeared to have lower rates of death specifically from heart disease and cardiovascular problems. The differences were noticeable enough that researchers felt they were worth reporting, suggesting a real connection rather than just random chance.

The study found that the benefits appeared to increase with higher intake of these foods—meaning people who ate more fermented foods tended to have better outcomes than those who ate smaller amounts. This dose-response relationship (more food equals better results) makes the findings more convincing because it follows a logical pattern.

These results were particularly important for kidney disease patients because they typically face much higher risks of heart disease and early death compared to people with healthy kidneys. Finding that a simple dietary change might help reduce these risks is potentially valuable for this vulnerable population.

The research likely examined whether the benefits were similar across different groups of people (different ages, genders, or races) and whether other factors affected the results. The study probably also looked at whether the type of fermented food mattered or if all sources of live bacteria were equally beneficial.

Previous research has shown that live bacteria in foods (probiotics) can benefit digestive health and may help reduce inflammation in the body. This study builds on that knowledge by specifically looking at whether these benefits extend to heart health and survival in people with kidney disease. The findings align with growing evidence that gut health is connected to heart health, even in people with serious conditions like kidney disease.

The study can only show that eating these foods is connected to better health outcomes—it cannot prove the foods caused the improvement. People who eat more fermented foods might also exercise more, eat more vegetables, or have other healthy habits that actually caused the benefits. The study relied on people remembering what they ate, which can be inaccurate. Additionally, people with kidney disease need to be careful about certain foods, so the safety and appropriateness of these foods for all kidney disease patients wasn’t fully addressed in this research.

The Bottom Line

For people with chronic kidney disease: Consider adding fermented foods like plain yogurt, kefir, or sauerkraut to your diet, but only after discussing with your kidney disease doctor or dietitian. These foods may support heart health and overall survival, but kidney disease requires careful food choices due to concerns about potassium, phosphorus, and sodium. Confidence level: Moderate—the research suggests benefits, but more studies are needed to confirm. For people without kidney disease: This research doesn’t directly apply to you, though general population studies suggest probiotics may have health benefits.

People with chronic kidney disease should pay attention to this research, especially those concerned about heart health. Their doctors and dietitians should consider whether recommending these foods makes sense for their individual situation. People without kidney disease don’t need to change their habits based on this specific study, though general nutrition guidelines often recommend fermented foods. People with severe kidney disease or those on dialysis should be especially cautious and get personalized advice.

If you start eating more fermented foods, you shouldn’t expect immediate changes. Health benefits from dietary changes typically take weeks to months to become noticeable. For serious outcomes like reducing death risk, the benefits would likely show up over years of consistent eating habits. Be patient and consistent, and work with your healthcare team to monitor your health.

Want to Apply This Research?

  • Log fermented food intake weekly (yogurt servings, sauerkraut portions, kefir drinks) and track alongside kidney function markers and blood pressure readings to see if patterns emerge over time
  • Set a goal to include one serving of kidney-safe fermented food daily (like plain, low-sodium yogurt) and use app reminders to build this habit consistently
  • Track fermented food consumption monthly, monitor kidney function tests and cardiovascular markers quarterly with your doctor, and note any changes in energy levels or overall wellbeing to identify personal patterns

This research suggests a connection between eating fermented foods and better health outcomes in people with kidney disease, but cannot prove the foods directly caused the improvement. People with chronic kidney disease have specific dietary restrictions regarding potassium, phosphorus, and sodium that vary based on their individual condition and stage of disease. Before making any dietary changes, especially if you have kidney disease, consult with your nephrologist (kidney doctor) or registered dietitian. This information is for educational purposes and should not replace personalized medical advice. Do not use this research to delay or avoid medical treatment.