The gut microbiome and short-chain fatty acids

A Mediterranean-inspired diet improves glucose metabolism, insulin sensitivity, and the composition and function of the gut microbiome in a population of overweight individuals at high cardio-metabolic risk, an intervention study carried out as part of a European project by researchers from the University of Frederick shows .

The research, just published in the scientific journal Clinical Nutrition, shows how adherence to a diet inspired by the Mediterranean model improves glucose metabolism and insulin sensitivity in the postprandial period through modification of the gut microbiota and increased plasma levels of butyric acid, a product of fermentation of dietary fiber by the microbiota.

This study is part of the European project DINAMIC - (Diet-induced Arrangement of the gut Microbiome for Improvement of Cardiometabolic health) whose first results were recently published in the journal Gut. The study was carried out by the research team consisting of Professor Angela Albarosa Rivellese and Dr. Marilena Vitale of the Federico II Department of Clinical Medicine and Surgery and Dr. Rosalba Giacco of the CNR Institute of Food Science, together with the research group of Professor Danilo Ercolini and Professor Paola Vitaglione of the Federico II Department of Agrariai, groups also afferent to the University Task Force for Microbiome Studies (www.tfm.unina.it).

The researchers evaluated in overweight/obese individuals the effects of a diet based on the Mediterranean model compared to a control diet on postprandial glycemic metabolism. The main results of the research show that the Mediterranean diet improves postprandial metabolism by preventing excessive increases in blood glucose and insulinemia, which, in the long run, can condition an increased risk for diabetes and cardiovascular disease.In addition, for the first time, these metabolic effects are shown to be related to a change in the composition of the gut microbiota, specifically an increase in the relative abundance of bacteria capable of fermenting fiber and an increase in plasma levels of butyric acid produced by these bacteria. In particular, the increase in butyric acid appears to be closely related to improved postprandial metabolic response and enhanced efficacy of insulin action.

The Mediterranean Diet, in addition to other previously highlighted positive effects, also acts specifically and positively on postprandial glycid metabolism, contributing, again, to the reduction of the risk of diabetes, myocardial infarction, and other cardiovascular diseases.