Intestinal bacteria determine the severity of atherosclerosis
Swedish researchers from Chalmers University of Technology have found that the composition of the microflora inhabiting the intestine determines a person's predisposition to diseases such as heart attacks and strokes caused by vascular blockage by detached atherosclerotic plaques. Compared with healthy people, fewer bacteria synthesizing compounds with anti-inflammatory properties live in the intestines of patients with diseases that are complications of atherosclerosis. Moreover, their microflora contains more microorganisms that produce molecules that trigger inflammatory processes.
This may explain the observation that people with a high content of antioxidants in adipose tissue, such as beta-carotene and lycopene, are less at risk of developing heart disease, but changing the diet or introducing appropriate dietary supplements does not have the desired effect.
With age, all people develop atherosclerosis to one degree or another. However, even with the same narrowing of the lumen of the arteries, some people are more at risk of heart attacks and strokes than others. This difference is due to the stability of plaques deposited on the inner surface of blood vessels, which reduce the elasticity of the walls and reduce the lumen of the arteries. Detached fragments of these plaques can block the flow of blood to the heart or brain, which leads to a heart attack or stroke.
The results of earlier studies indicate that the intestinal microflora can contribute to the development of atherosclerosis by converting chemical compounds contained in fatty foods into molecules deposited on arterial walls. The authors decided to find out whether there is a relationship between the vital activity of intestinal bacteria and the stability of atherosclerotic plaques. To do this, they analyzed the composition of microflora isolated from the feces of 13 healthy people and 12 patients with atherosclerosis who had moderate strokes, blockages of blood vessels of the brain or transient blindness due to thrombosis of the vessels of the eyes.
The intestinal microflora of most of the study participants belonged to one of the three main types of bacterial communities (enterotypes). In patients with atherosclerosis, enterotype 3 was significantly more often detected, which is characterized by the presence of a large number of bacteria of the genus Ruminococcus (Ruminococcus), as well as an increased content of bacteria of the genus Collinsella (Collinsella). Moreover, representatives of the intestinal microflora of patients had more genes responsible for the synthesis of the bacterial wall component peptidoglycan, known for its ability to trigger inflammatory processes.
In the faeces of healthy people, on the contrary, Eubacterium, Roseburia and Bacteroides predominated. They were also characterized by a relatively high content of clostridium (Clostridium). These bacteria are very often carriers of genes encoding butyrate, a compound with anti–inflammatory properties. Scientists have also found that the bacteria of healthy people have many genes that ensure the production of other inflammation-suppressing substances, such as lycopene and beta-carotene.
The authors believe that over time, the result of the analysis of the composition of the intestinal microflora, along with the level of cholesterol in the blood, will become an integral component of the complex of prognostic factors for assessing the risk of heart attack and stroke.
Article by Fredrik H. Karlsson et al. Symptomatic atherosclerosis is associated with an altered gut metagenome published in the journal Nature Communications.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on Chalmers University of Technology:
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