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A new study published in The American Journal of Clinical Nutrition found that adhering to a low-calorie Mediterranean diet alongside physical activity yields significant cardiovascular benefits.
The research suggests these lifestyle changes impact cardiovascular health by altering the colon’s bacterial composition and metabolite production.
The findings represent a substantial advancement in understanding preventive measures against cardiovascular diseases, which are the primary cause of death in developed nations.
See Also:Health NewsThe Mediterranean diet has long been associated with positive gut microbes and metabolites, yet its effect on the fecal metabolome is poorly understood.
The traditional Mediterranean diet involves a high intake of vegetables, fruits, legumes and nuts, moderate consumption of fish, low consumption of meat, moderate alcohol and extra virgin olive oil as the primary fat source.
Greater adherence to the Mediterranean diet correlates with beneficial gut bacteria and metabolites, attributed to increased fiber-degrading species and anti-inflammatory responses.
However, its effects on gut microbiota and plasma metabolome are inconsistent across studies, with unclear impacts on cardiovascular disease risk factors.
With the latest study, researchers aimed to assess the weight-loss impact of a year-long lifestyle intervention based on an energy-reduced Mediterranean diet with physical activity (intervention group) compared to an ad libitum Mediterranean diet (control group) on fecal metabolites, microbiota and their links to cardiovascular disease risk factors.
The intervention affected four stool metabolites, primarily composed of bile acids, ceramides, sphingosines, fatty acids, carnitines, nucleotides and purine and Krebs cycle metabolites.
The study involved 400 participants aged 55 to 75 at high cardiovascular risk, and data were collected at baseline and after a year.
The researchers found that the intervention group exhibited greater weight loss and improved cardiovascular risk factors compared to the control.
These changes were associated with alterations in cardiovascular disease risk factors. Moreover, certain gut bacteria genera were reduced, and alpha diversity increased in the intervention group.
The study’s results suggested an interplay between diet, metabolites and gut microbiota. While previous studies focused on plasma or urine metabolites, few explored the fecal metabolome.
Results from participants with obesity and metabolic syndrome indicated reductions in plasma cholesterol and fecal bile acid (metabolites involved in nutrient absorption) concentrations after the Mediterranean diet intervention.
See Also:Mediterranean Diet and Exercise Improve Working Memory in Young StudentsThe intervention enriched gut bacterial genera linked to bile acid metabolism and increased fecal cadaverine, which is associated with improved insulin sensitivity.
Participants in the intervention group showed more significant reductions in adiposity (fat tissue accumulation) and improvements in lipid profile and glucose markers.
Furthermore, decreases in the abundance of E. hallii and Dorea spp. were observed in the intervention group, linked to changes 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.
The researchers acknowledged that the study had some limitations. The participants were older Mediterranean adults with specific health conditions, so generalizing the results to other populations may not be appropriate.
Additionally, the sequencing method used in the study limits taxonomic profiling to the genus level, hindering differentiation between closely related bacteria and limiting the ability to infer functionality.
However, the study has notable strengths. Despite the non-representative sample, the findings are relevant for a significant portion of the global population at high risk of cardiometabolic diseases.
The randomized controlled design allowed for establishing causality and assessing intervention effects, with adjustments made for significant confounders, reducing residual confounding. Although the sequencing method has limitations, it is suitable for analyzing many samples.
Beyond individual health outcomes, the researchers said understanding the impact of these interventions on the gut microbiome sheds light on mechanisms underlying improved cardiometabolic biomarkers.
They hope this knowledge will inform targeted public health strategies and personalized health recommendations, tailoring interventions based on individual microbiome profiles for more effective prevention and management of cardiometabolic diseases.