Researchers looked at data from over 12,000 American adults to understand how diet affects a special protein in our blood called Klotho, which helps us age more slowly. They found that people who ate foods that are good for their gut bacteria had higher levels of this anti-aging protein. The connection seemed to work partly through reducing inflammation in the body. This suggests that choosing foods that support healthy gut bacteria might be one way to help our bodies stay younger and healthier as we get older.

The Quick Take

  • What they studied: Whether eating foods that are good for gut bacteria is connected to having higher levels of a protein that helps slow aging, and whether reducing body inflammation is part of how this works.
  • Who participated: 12,341 adults between ages 40 and 79 from the United States who participated in a national health survey between 2007 and 2016.
  • Key finding: Adults who ate the most gut-friendly foods had about 22 points higher levels of the anti-aging protein Klotho compared to those who ate the least, and this difference was statistically significant (p = 0.002).
  • What it means for you: Eating foods that support healthy gut bacteria may help boost an important anti-aging protein in your body. However, this study shows a connection, not proof that diet directly causes higher Klotho levels. More research is needed before making major dietary changes based on this finding alone.

The Research Details

This was a cross-sectional study, which means researchers looked at information collected from thousands of people at one point in time, rather than following people over many years. The researchers used data from the National Health and Nutrition Examination Survey (NHANES), a large government study that tracks the health of Americans.

The study measured three main things: First, they calculated a “Dietary Index for Gut Microbiota” score based on what people reported eating—this score reflects how well someone’s diet supports healthy gut bacteria. Second, they measured levels of a protein called Klotho in people’s blood using a lab test. Third, they measured inflammation markers by analyzing blood samples to see how much inflammation each person had in their body.

The researchers then used statistical tools to see if people with higher gut-friendly diet scores also had higher Klotho levels, and whether inflammation played a role in this connection.

This approach matters because it looks at real-world data from thousands of actual people rather than a small lab experiment. By studying such a large group, the findings are more likely to apply to the general population. The researchers also looked at inflammation as a possible explanation for why diet might affect Klotho levels, which helps us understand the mechanism behind the connection.

Strengths of this study include the large sample size (over 12,000 people) and use of standardized measurements from a well-established national survey. The researchers adjusted their analysis for many factors that could affect the results, like age, sex, and other health conditions. However, because this is a cross-sectional study, it shows associations but cannot prove that diet directly causes changes in Klotho levels. The study also relied on people’s memory of what they ate, which can be inaccurate.

What the Results Show

The main finding was that people who ate more foods supporting healthy gut bacteria had significantly higher levels of the anti-aging protein Klotho. Specifically, for every one-point increase in the gut-friendly diet score, Klotho levels increased by about 4 points. When comparing people with the highest diet scores to those with the lowest, the difference was even more dramatic—about 22 points higher.

The relationship between diet and Klotho appeared to be linear, meaning that as people ate better for their gut bacteria, their Klotho levels went up in a steady, predictable way. This pattern held true even after researchers adjusted for many other factors that could affect Klotho levels, such as age, weight, and existing health conditions.

Interestingly, the connection was stronger in people who didn’t drink alcohol. This suggests that alcohol might interfere with how diet affects Klotho levels, though more research would be needed to confirm this.

The mediation analysis revealed that inflammation played a partial role in explaining the connection between diet and Klotho. Two different inflammation markers—the systemic immune-inflammation index and the systemic inflammation response index—each explained about 5-7% of the relationship. This means that part of the benefit of eating gut-friendly foods comes from reducing inflammation, but most of the effect works through other mechanisms not yet fully understood.

This study builds on previous research showing that Klotho levels are important for healthy aging and that gut bacteria influence many aspects of our health. However, this appears to be one of the first studies to directly examine how a diet specifically designed to support gut bacteria affects Klotho levels. The finding that inflammation partially explains this relationship aligns with growing evidence that gut health, inflammation, and aging are all connected.

This study has several important limitations. First, it’s cross-sectional, meaning we can see that diet and Klotho levels are connected, but we cannot prove that changing your diet will change your Klotho levels. Second, the study relied on people remembering what they ate, which is often inaccurate. Third, the study only included American adults aged 40-79, so results may not apply to younger people or other populations. Finally, the inflammation markers only explained a small portion of the relationship, suggesting other important mechanisms are still unknown.

The Bottom Line

Based on this research, eating foods that support healthy gut bacteria appears to be associated with higher levels of an anti-aging protein. However, this is preliminary evidence. A reasonable approach would be to focus on eating more fiber-rich foods, fermented foods, and plant-based foods, which generally support gut health and have other proven health benefits. This should not replace advice from your doctor, especially if you have existing health conditions. Confidence level: Moderate—the study is large and well-designed, but it shows association, not causation.

This research is most relevant to middle-aged and older adults (40+) who are interested in healthy aging. People concerned about inflammation or aging-related diseases may find this particularly interesting. However, this research should not be used to make major dietary changes without consulting a healthcare provider. People with specific dietary restrictions or medical conditions should discuss any dietary changes with their doctor.

If dietary changes do affect Klotho levels, the timeline is unknown. Changes in gut bacteria can occur within weeks of dietary changes, but it’s unclear how quickly this would translate to changes in Klotho levels or whether you would notice any health benefits. Realistic expectations would be to give any dietary changes at least 2-3 months before assessing results, and to focus on overall health improvements rather than Klotho levels specifically.

Want to Apply This Research?

  • Track daily intake of gut-friendly foods: servings of fiber (whole grains, vegetables, fruits), fermented foods (yogurt, kefir, sauerkraut), and plant-based proteins. Aim for a specific target like 25-30g of fiber daily and at least 2-3 servings of fermented foods per week.
  • Users could set a daily reminder to include one gut-friendly food at each meal—for example, adding beans to lunch, choosing whole grain bread, or including a serving of vegetables with dinner. The app could suggest specific foods and track progress toward weekly goals.
  • Over 8-12 weeks, track consistency with the gut-friendly diet using the app’s food logging feature. Monitor general health markers like energy levels, digestion, and inflammation symptoms (if applicable). Consider periodic blood work through a healthcare provider to measure actual Klotho levels if interested in objective measurement, though this is not necessary for most people.

This research shows an association between diet and Klotho levels but does not prove that changing your diet will change your Klotho levels or improve your health. This information is for educational purposes only and should not replace professional medical advice. Before making significant dietary changes, especially if you have existing health conditions, take medications, or have dietary restrictions, please consult with your healthcare provider or a registered dietitian. The findings apply specifically to adults aged 40-79 and may not apply to other age groups or populations.