Gut microbes could influence the health effects of Mediterranean diet

The gut microbiota make-up could determine whether a person will benefit from the beneficial effects of the Mediterranean diet.
Table of Contents

• Healthy diet
• Swaying benefits

What is already known on this topic
The Mediterranean diet, which is rich in vegetables, fruits, legumes, nuts, and unsaturated fats such as olive oil, has been associated with reduced risk of a variety of diseases, including those affecting the heart and the cardiovascular system. But how the gut microbiota influences the interaction between diet and cardiometabolic health remains unclear.

What this research adds
Researchers analyzed the dietary habits and the gut microbiota of more than 300 healthy men. Individuals who adhered to a Mediterranean diet tended to have reduced cardiometabolic disease risk as well as a different gut microbiota composition, with higher levels of bacteria such as Faecalibacterium prausnitzii and Bacteroides cellulosilyticus, which are known to metabolize dietary fiber. These individuals also had lower levels of a bacterial species called Prevotella copri, and they appear to benefit the most from the positive effects of the Mediterranean diet on cardiometabolic disease.

Conclusion
The findings could inform dietary approaches to prevent cardiometabolic disease through alterations in the gut microbiota, and they support the development of personalized nutrition plans that take into account an individual’s gut microbes.

The Mediterranean diet has been linked to reduced risk of cardiovascular disease. Now, researchers have found that the gut microbiota make-up could determine whether a person will benefit from the beneficial effects of this diet.

The findings, published in Nature Medicine, could inform dietary approaches to prevent cardiometabolic disease through alterations of the gut microbiota. They also support the development of personalized nutrition plans that take into account an individual’s gut microbes, the researchers say.

The Mediterranean diet is rich in vegetables, fruits, legumes, nuts, and unsaturated fats such as olive oil, and poor in red meats and refined grains. The diet has been associated with reduced risk of developing a variety of diseases, including those affecting the heart and the cardiovascular system.

To assess how the gut microbiota influences the interaction between diet and cardiometabolic health, Curtis Huttenhower at the Harvard T.H. Chan School of Public Health and his colleagues analyzed the dietary habits and the gut microbiota of more than 300 healthy men.

Healthy diet

Study participants were asked to take stool samples every six months for two years and fill out a questionnaire about their diets.

Those who adhered to a Mediterranean diet tended to have a different gut microbiota composition, with higher levels of bacteria such as Faecalibacterium prausnitzii and Bacteroides cellulosilyticus, which are known to metabolize dietary fiber. These individuals also showed fewer hallmarks of disease risk, including inflammation and high blood sugar levels.

Since the Mediterranean diet is mostly plant-based, the researchers found microbial functions associated with the degradation of fibers and short chain fatty acids in the gut of people who followed such diet.

Swaying benefits

Adherence to the Mediterranean diet was also associated with lower levels of a bacterial species called Prevotella copri. People with decreased levels of P. copri appear to benefit the most from the positive effects of the Mediterranean diet on cardiometabolic disease, the researchers found.

“This finding supports the premise that dietary interventions or recommendations for cardiometabolic disease prevention could be tailored to an individual’s gut microbial profile,” the researchers say.

Although more research is needed to understand whether other factors might make some people more likely to benefit from the health effects of the Mediterranean diet, the study provides insights into the mechanisms that underlie host-microbiota interaction, and how that affects disease severity and progression, the authors say.