Adults with coronary heart disease (CHD) who follow diets supporting gut microbiota health may face a lower risk of all-cause mortality, according to a retrospective cohort analysis published in the journal Medicine. Researchers using NHANES data (2005–2018) found that participants with the highest Dietary Index for Gut Microbiota (DI-GM) scores had significantly lower death rates during follow-up compared to those with the lowest scores.
How does the DI-GM score affect heart disease survival?
A higher DI-GM score correlates with a lower risk of death in CHD patients. According to the study published in Medicine, participants with a DI-GM score of 5 or 6+ showed significantly lower mortality rates than the lowest-score group. While a score of 4 trended toward lower mortality, it didn’t reach statistical significance.
The researchers noted the relationship is nonlinear. This means mortality risk doesn’t drop by a fixed amount with every single point increase in the score, but rather shows a more complex pattern of benefit as dietary quality improves.
What foods influence gut microbiota and heart health?
The DI-GM score is calculated based on 14 specific dietary components. According to the research team, “positive” components that support a healthy gut include:
- Fiber and Grains: Whole grains and dietary fiber.
- Produce: Avocado, broccoli, and cranberries.
- Legumes and Seeds: Chickpeas and soybeans.
- Beverages: Green tea and coffee.
- Probiotics: Fermented dairy products.
Conversely, the index penalizes “adverse” components. These include red meat, processed meat, refined grains, and diets high in fat. The researchers suggest these microbes help regulate blood vessel function, fat metabolism, and inflammation.
Does diabetes change the impact of gut-healthy diets?
Yes. While the association between high DI-GM scores and lower mortality remained consistent across age, sex, BMI, and smoking status, the researchers found that diabetes status modified the relationship. This suggests that the nutritional management of the gut microbiota may be particularly relevant for CHD patients who also struggle with glycemic control.
What are the limitations of this research?
The authors of the Medicine study highlighted several caveats. The research was retrospective and relied on a single 24-hour dietary recall, which may not capture a person’s lifelong eating habits. Additionally, the data relied on self-reported disease information from the NHANES survey.
The researchers emphasized that while the association is evident, causal effects remain unproven. The study shows a correlation—meaning people who eat these foods tend to live longer—but doesn’t prove the diet alone caused the survival increase.
Frequently Asked Questions
What is the DI-GM score?
It is the Dietary Index for Gut Microbiota, a scoring system based on 14 foods and nutrients that either support or harm the microbes in the gut.
Who participated in the study?
The study used data from the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2018, focusing on a subset of 1,537 adults with coronary heart disease.
Does a high-fat diet lower the DI-GM score?
Yes, according to the study, a high-fat diet is listed as one of the adverse components that lowers the overall score.
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