Study finds that Mediterranean diet is associated with greater intestinal diversity

In a recent study published in the journal nutrientsresearchers investigated how practicing a Mediterranean diet (MD) affects the gut microbiota of healthy individuals through a well-defined cohort study.

Their results show that adhering to MD increases the species diversity of the microbiota, providing insight into how this can lead to measurable health benefits.

study: Effects of the Mediterranean diet on the gut microbiota of well-defined healthy people. Image credit: Marian Weyo / Shutterstock

background

Traditionally practiced in many Mediterranean communities, MD is a nutrient-dense diet centered on whole grains, healthy fats, fruits, and vegetables, which have antioxidant and anti-inflammatory properties.

It has been reported to improve cardiovascular health and reduce the risk of metabolic syndrome, neurodegenerative diseases, type 2 diabetes, and some cancers. This is in contrast to diets high in refined carbohydrates and fats, which have been implicated in an increase in obesity and multiple metabolic diseases.

The effects of different diets may be mediated by how they influence the gut microbiota, which plays an important role in disease prevention and health maintenance. Because dietary diversity, fat composition, and fiber intake all leave distinct imprints on the microbial community, specific dietary habits and food components associated with MD may enhance beneficial gut microbiota.

About research

For this study, researchers recruited healthy volunteers (donors and relatives) from fecal transplant clinics in Spain. Participants had a body mass index (BMI) of 17 to 30, had no known medical conditions or disorders, did not consume more than 50 grams of alcohol per day, and had not taken any vaccines or certain medications in the three months prior to the study. I wasn’t taking it.

Participants were stratified by age and provided demographic information, dietary intake via a food frequency questionnaire, and medical history. Their MD adherence was assessed using diet quality indicators. Those who received a score of 1–4 were classified as “good” adherent, and those who received a score of 5–9 were classified as “moderate” adherent.

The gut microbiome is determined by analyzing stool samples, identifying microbial species, and measuring species richness, the number of species found within a sample, and the evenness or similarity of the abundance of different species. It was evaluated by measuring sex (Pirou index).

The inverse Simpson index was used to indicate the richness of communities with the same evenness, while the Shannon index examined the number of species living in a particular habitat and their relative abundance.

Alpha diversity, which measures species diversity within a single individual, and beta diversity, which assesses differences in diversity between individuals, were also calculated. The researchers also calculated the correlation between microbial abundance and nutrient intake.

Investigation result

Of the 60 participants in the study, just over 50% were women and the median age was 31 years. On average, females had higher species richness and higher values ​​of Pirou index, inverse Simpson index, and Shannon index.

Firmicutes, Bacteroidetes, and Actinobacteria were the predominant phyla in males and females.Contains abundant genera Bifidobacterium, Bacteroides, Faecalibacterium, Prevotellaand Blautia.meanwhile Bacteroides There were many of all age groups, Bifidobacterium As I get older, my control becomes weaker.

Children consistently had lower values ​​than other groups on all diversity indices. Teenagers had the highest values ​​for affluence, and older adults (49 years and older) had high Pirou, Shannon, and reverse Simpson values. When we stratified these results by sex, we found that these differences remained for males but not for females, except that species evenness persisted in both.

The median dietary adherence score of the 39 people who completed the meal frequency questionnaire was 5. The median age of those with good dietary adherence was 48 years, while those with moderate adherence were younger, with a median age of 30 years.

Improved MD adherence was associated with higher MD adherence Bacteroides and paraprevotella However, there were no gender differences in alpha and beta diversity indices. Stratifying by age, the researchers found that better compliance reduced the abundance of different genera in different groups.

Correlation analysis showed that fat intake was negatively correlated with Shannon index, while non-starch polysaccharides (NSP) and total carbohydrates were positively correlated. The Pielou index was directly correlated with total carbohydrates and NSP, while negatively correlated with red meat intake.

People with better adherence also showed differences in pathways associated with bladder cancer, polycyclic aromatic hydrocarbon breakdown, and water reabsorption regulated by vasopressin. They showed many more enzymes related to lipid metabolism and various biosynthetic processes.

conclusion

In this study, we evaluated the impact of MD on the gut microbiota through well-defined cohorts based on gender and age, and found that there are significant differences in alpha and beta diversity associated with microbial composition and adherence. It turns out. These findings were strengthened by the identification of distinct functional pathways and specific bacterial taxa based on adhesion levels.

The small size of the study sample may limit the generalizability of these results. Further studies using longitudinal designs and larger cohorts are needed to better understand how MD can enhance the microbiome and enhance health outcomes.