A human’s microbiome – that is, the type of bacteria that colonize our gastrointestinal tract – differs from person to person in adults and has pronounced effects on the body. A new study with the participation of University Hospital Zurich reveals that the microbiome influences the prognosis in patients suffering from a heart attack.
Bacteria in the stomach break down the food we ingest into various metabolites, chemical compounds produced by the action of enzymes. These are then absorbed via the intestinal tract and ultimately influence the function of various organs and processes in the body. For example, bacteria convert the lecithin and other substances found in meat products, eggs and high-fat dairy products into trimethylamine N-oxide or TMAO, a decomposition product that has an adverse effect on the cardiovascular system.
In a large-scale study with a total of more than 2,000 patients conducted by Cleveland Clinic and the cardiology team from University Heart Center Zurich at UHZ, the Swiss/American authors show that the blood TMAO level influences disease progression following a heart attack. High TMAO levels are thus associated with an increased risk of another heart attack and heart failure. The study was published recently in the European Heart Journal (see references at end of article).
Interestingly, American patients showed higher TMAO values than Swiss patients – possibly as a result of higher meat consumption. Similarly, complications following a heart attack were more frequent in American than Swiss patients. This suggests that differences in nutrition and microbiome have a significant influence on the prognosis following a heart attack.
The discovery that body-borne bacteria influence our health is a completely novel concept in cardiology. Further studies must now reveal whether and what type of dietary change reduces the risk of further events and death in heart attack patients with high levels of TMAO in the blood.
Contact in case of queries:
Prof. Thomas F. Lüscher, Director of the Department of Cardiology and Director of University Heart Center Zurich, University Hospital Zurich, cardio@tomluescher.ch or +41 44 255 21 21.
Study: “Gut microbiota-dependent trimethylamine N-oxide in acute coronary syndromes: a prognostic marker for incident cardiovascular events beyond traditional risk factors”, by Xinmin S. Li et al. European Heart Journal. doi:10.1093/eurheartj/ehw582
The study is available online at http://eurheartj.oxfordjournals.org/content/early/recent