A recent study published in The American Journal of Clinical Nutrition unveils compelling evidence regarding the positive impact of adhering to a low-calorie Mediterranean diet alongside regular physical activity on cardiovascular health in older adults. The research suggests that these lifestyle modifications not only influence cardiovascular markers but also alter the composition of bacteria in the colon and the production of metabolites, representing a significant advancement in preventive measures against cardiovascular diseases, which remain a leading cause of mortality in developed nations.
The Mediterranean diet, renowned for its health benefits, emphasizes the consumption of vegetables, fruits, legumes, nuts, fish, and moderate alcohol, while limiting meat intake and favoring extra virgin olive oil as the primary fat source. Previous studies have linked the Mediterranean diet to favorable gut microbes and metabolites, yet its specific effects on the fecal metabolome have remained poorly understood.
The study, conducted over a year-long period, aimed to assess the impact of a lifestyle intervention based on an energy-reduced Mediterranean diet coupled with physical activity compared to an ad libitum Mediterranean diet on fecal metabolites, microbiota, and their association with cardiovascular disease risk factors. The intervention involved 400 participants aged 55 to 75, all at high cardiovascular risk, with data collected at baseline and after the intervention period.
Results from the study revealed significant alterations in fecal metabolites, primarily consisting of bile acids, ceramides, sphingosines, fatty acids, carnitines, nucleotides, purine, and Krebs cycle metabolites. Participants in the intervention group exhibited greater weight loss and improvements in cardiovascular risk factors compared to the control group. Notably, certain gut bacteria genera were reduced, while alpha diversity increased in the intervention group.
Moreover, participants with obesity and metabolic syndrome experienced reductions in plasma cholesterol and fecal bile acid concentrations following the Mediterranean diet intervention. The intervention also enriched gut bacterial genera associated with bile acid metabolism and increased fecal cadaverine levels, linked to improved insulin sensitivity.
Furthermore, participants in the intervention group demonstrated significant reductions in adiposity and improvements in lipid profile and glucose markers. Changes in the abundance of specific gut bacteria, such as E. hallii and Dorea spp., were observed, correlating with alterations in fecal metabolites and cardiovascular risk factors. E. hallii is implicated in glucose metabolism and insulin resistance, while Dorea spp. is associated with prediabetes and elevated blood glucose levels.
Despite some limitations, including the non-representative sample and taxonomic profiling constraints, the study’s randomized controlled design allowed for establishing causality and assessing intervention effects. The findings hold relevance for a significant portion of the global population at high risk of cardiometabolic diseases and offer valuable insights into targeted public health strategies and personalized health recommendations.
By understanding the impact of lifestyle interventions on the gut microbiome, researchers hope to develop more effective prevention and management strategies for cardiometabolic diseases, tailored to individual microbiome profiles. This knowledge has the potential to revolutionize public health initiatives and improve health outcomes on a global scale.