The Mediterranean dietary pattern has been largely associated with improved health outcomes. Two new randomized controlled trials reveal the contribution of gut microbiome composition and functions to explaining the potential beneficial effects of the Mediterranean diet. People following a Mediterranean diet MedDiet —characterized by low intake of refined cereal products, dairy and meat products and higher amounts of vegetables, fruits, legumes, whole grains, fish and a daily serving of nuts—show the best overall health and appear to be protected from metabolic-related diseases, cancer and even mental health-related disorders. It should be acknowledged that participants in the MedDiet group were instructed to improve the quality of their diet without changing their habitual energy intake, macronutrient intake or physical activity. In the MedDiet subjects, a reduction in total plasma cholesterol was reported as early as 4 weeks after the beginning of the diet. In addition, lower total high-density lipoprotein HDL and low-density lipoprotein LDL cholesterol was observed at the end of the intervention, which was proportional to MedDiet adherence rates. Metabolomic analyses of feces, urine and blood showed that the MedDiet was characterized by higher levels of the biomarkers of whole grains, legumes — commonly used as biomarkers of plant food intake— vegetables and nuts, together with reduced concentrations of the biomarkers of meat and protein degradation products. Although MedDiet consumption was related to a reduction in fecal levels of bile acids and branched-chain fatty acids when compared with the conventional diet group, the high fiber intake did not affect fecal levels of short-chain fatty acids. These studies show that one of the ways by which the MedDiet is linked to better metabolic health and healthy ageing is through positive changes in the gut microbiome.
Exercise and diet are often cited as the best ways of maintaining good health well into our twilight years. But recently, research has also started to look at the role our gut — specifically our microbiome — plays in how we age. Our latest study has found that eating a Mediterranean diet causes microbiome changes linked to improvements in cognitive function and memory, immunity and bone strength. The gut microbiome is a complex community of trillions of microbes that live semi-permanently in the intestines. They also help prevent disease-causing bacteria from growing. However, the gut microbiome is extremely sensitive, and many things including diet, the medications you take, your genetics, and even conditions like inflammatory bowel disease and irritable bowel syndrome, can all change the gut microbiota community. Since our everyday diets have such a big affect on the gut microbiome, our team was curious to see if it can be used to promote healthy ageing. We asked half of them to change their normal diet to a Mediterranean diet for a full year. This involved eating more vegetables, legumes, fruits, nuts, olive oil and fish, and eating less red meat, dairy products and saturated fats.
Bibbins-Domingo K. Devereux G. Willett W. Further studies will need to focus on what key nutrients and food staples in a MedDiet are responsible for these positive gut microbiome changes and who will benefit the most. These diet-positive microbes were linked with less frailty and inflammation in the body, and higher levels of cognitive function. Related articles A new study characterizes the cellular topology and diversity of the enteric nervous system in mice and humans using novel methodologies 9 Nov by GMFH Editing Team. Dietary patterns and breast cancer risk: A systematic review and meta-analysis.