Mediterranean Diet Stimulates good Intestinal Bacteria

The Mediterranean diet characterized by a diet rich in fruits, vegetables, seeds and seafood is often presented as a dietary habit to follow to limit the risk of chronic diseases. Inserm believes for example in a study on the nutritional prevention of osteoporosis that "the Mediterranean diet, known for its protective properties vis-à-vis the development of certain cancers and cardiovascular diseases, could be interesting" because its richness in micronutrients and monounsaturated fatty acids. American researchers are evoking in a new study another reason to adopt it: it is good for the intestine.

Scientists at the Wake Forest Baptist Medical Center have found that a diet rich in plant foods improves the good bacteria living in the gut by 7%, compared to 0.5% for a Western diet more focused on meat. With primates, the research team established Western-style or Mediterranean style diets for the latter, monitored and analyzed over a 30-month period. "Long-term diet studies are usually based on self-reported dietary intake collected through questionnaires with estimated nutritional intake only," said lead author Hariom Yadav.

The gut microbiota is more balanced

The Western diet consisted of consuming lard, beef, butter, eggs, high-fructose corn syrup and sucrose, while the Mediterranean diet consisted of eating fish and olive oil, eggs, chickpea and black bean flour, vegetable juices and fruit purées. If both diets had the same number of calories, they did not have the same impact on the intestinal microbiota (the good and bad bacteria that live in the gastrointestinal tract) of primates. Stool tests revealed that the diversity of intestinal bacteria was significantly higher in the "Mediterranean diet" group.

Specifically, the study indicates a significantly higher presence of good bacteria primarily from the Lactobacillus family in this group. These are considered as probiotics, living micro-organisms that, when consumed in adequate quantities, are beneficial to human health. "We have about 2 billion good and bad bacteria living in our gut. If the bacteria are of a certain type and unbalanced, our health can suffer, "says Professor Hariom Yadav. However, according to Inserm, an imbalance of the microbiota is linked to certain pathologies, in particular autoimmune and inflammatory diseases.

For researchers, the data revealed in this study may prove useful for further work aimed at understanding the food-microbiota-health interactions in humans, including obesity, type 2 diabetes, cardiovascular disease, and psychiatric disorders. In addition to a balanced diet or not, several studies on the subject have shown that other factors are known to modify qualitatively and quantitatively the composition of the intestinal flora. Negatively as repeated medical treatments (antibiotics) or beneficial as changes in lifestyle and oral intake of probiotics and prebiotics.