20% of patients over 65 are diagnosed with peripheral arterial disease, associated with a high risk of myocardial infarction, ischemic stroke, limb amputation and death. A Spanish study tries to guide personalized preventive guidelines thanks to a molecule produced by the intestinal flora.
Researchers at the Cima University of Navarra and the Hospital Complex of Navarra (CHN) have shown that a molecule of intestinal bacteria predicts the risk of mortality in patients with peripheral arterial disease. The results of this work, carried out under the Health Research Institute of Navarra (IdiSNA), were published in Scientific Reports.
Patients with peripheral arterial disease have high levels of arteriosclerosis, chronic inflammation of the arteries and pain in the lower extremities. Depending on the degree of disease, their quality of life decreases significantly.
“The main problem is that the symptoms manifest when the disease is advanced, which reduces the effectiveness of the treatment. In this work we have studied the levels of trimethylamine-N-oxide (TMAO), a metabolite derived from intestinal bacterial flora, which is associated with risk of atherosclerosis,” explains Carmen Roncal, researcher at the Top University of Navarra and first author of the work.
“Using a mass spectrometry technique, we evaluate its association with the severity and prognosis of the disease and confirm that patients with high TMAO show an increased risk of cardiovascular death,” she adds.
The study is part of a collaboration initiated in 2010 between Cima and the CHN. “We have recruited blood samples from more than 300 patients, reviewed their medical history and recorded the presence of cardiovascular events or the cause of death, if applicable, and correlated it with possible biomarkers. Specifically, we have studied the relevance of TMAO as a prognostic factor in these patients,” points out Esther Martínez-Aguilar, researcher at the Department of Angiology and Vascular Surgery of the CHN.
The work concludes that TMAO is an effective biomarker to predict the presence of serious cardiovascular pathology in patients with peripheral arterial disease. According to José Antonio Páramo, senior researcher at Cima and the Clínica Universidad de Navarra and group leader at the Center for Biomedical Research in Network for Cardiovascular Diseases (CIBERCV), the blood detection for their biomarker requires sophisticated techniques; therefore they must continue working to achieve measuring its levels through a conventional blood test.
Since TMAO is generated in intestinal bacteria, the production of this metabolite is directly related to food. “We know that the intake of red meat, eggs, shellfish, dairy, etc. encourage intestinal bacteria to metabolize these foods to intermediate molecules, which after being absorbed by the body, give rise to TMAO by the action of liver enzymes. Therefore, following a healthy diet can help modify the intestinal microbiota, so as to reduce the production of harmful metabolites for each patient,” conclude the authors of the work.