Wednesday 4 July 2018

Toxic metabolites affect the development of atherosclerosis

Some people are more susceptible to developing atherosclerosis. Toxic metabolites from the intestinal microbiome play an important role in this. Treatment with, amongst other things, probiotics may offer a solution. 

Too few healthy gut bacteria are linked to all sorts of disorders, such as type 2 diabetes, obesity and inflammation of the stomach and intestine. In a recent study, this was also associated for the first time with atherosclerosis, or hardening of the arteries, which is considered to be one of the main causes of heart attacks and strokes. [1]


Unexplained plaque formation

A new study performed at the University of Western Ontario reveals that the intestinal microbiome plays an important role in the individual risk of atherosclerosis. And that opens new perspectives to patients with inexplicable plaque formation in the arteries (which leads to hardening). The study was published in the Atherosclerosis journal. [2]


Toxic metabolites

To understand the role that gut bacteria play, researchers measured the levels of metabolites in the blood that produce gut bacteria. They studied a total of 316 people from three different patient groups:

  1. A group with plaque in the arteries, caused by known risk factors, such as smoking, high blood pressure, overweight, diabetes and protracted stress;
  2. A group with normal arteries, despite the fact that they are known to have the aforementioned common risk factors. They therefore did not appear to be susceptible to atherosclerosis;  
  3. A group with unexplained atherosclerosis: the aforementioned risk factors did not apply to them, but despite this, they were susceptible to plaque formation. 

Researchers mainly focussed on the metabolites TMAO, p-cresol sulphate, p-cresol glucuronide and phenylacetylglutamine and using ultrasound measured the plaque in the carotid arteries. The patients from the third group, with unexplained atherosclerosis, had significantly higher blood values of these toxic metabolites. 
The difference between the three groups could not be explained by the diet or kidney function, but therefore by a difference in terms of the metabolites produced by the gut bacteria. [3]


Probiotics and faecal transplants

Further to the study, the researchers concluded that toxic metabolites play an important role in the individual risk of atherosclerosis, and that opens up possibilities for the third group of patients: “The outcomes of this study present us with the opportunity to use probiotics to combat these toxic metabolites and to reduce the risk of cardiovascular disease.” Another researcher adds that faecal transplants could also offer a solution in this case. 



[1] Cristina Menni et al. Gut microbial diversity is associated with lower arterial stiffness in women, European Heart Journal (2018). DOI: 10.1093/eurheartj/ehy226 

[2] Chrysi Bogiatzi et al, Metabolic products of the intestinal microbiome and extremes of atherosclerosis, Atherosclerosis (2018). DOI: 10.1016/j.atherosclerosis.2018.04.015