Approach for future therapies: Special bacteria in the intestine can digest cholesterol

Enlarge image

Beef burgers: Animal fats can lead to an increase in cholesterol in the blood

Photo: Getty Images

Certain bacteria in the intestine can break down cholesterol. In a correlation study, US researchers found less cholesterol in the intestines and blood of people with high concentrations of these bacteria. This is what the team led by Ramnik Xavier from the Broad Institute in Cambridge, USA, reports in the journal “Cell”.

High cholesterol levels increase the risk of cardiovascular disease. It is known that the level is influenced by various factors: genes, diet and lifestyle. As early as 2020, Xavier and other researchers showed that the diversity of bacteria in the intestine, the microbiome, can also break down cholesterol. However, in the work at that time, the individual types of bacteria and their metabolism were not analyzed in detail.

Samples from more than 1400 participants

The team now used data and stool samples from more than 1,400 participants in the Framingham Heart Study. This has been systematically examining people for the causes and risks of cardiovascular diseases for more than 70 years. In the laboratory, the researchers decoded all of the microbes’ DNA from the samples. In addition, they also recorded thousands of metabolic products using a novel technique.

The researchers found numerous possible connections between various intestinal bacteria and risk factors for the cardiovascular system. A main result: People with a particularly large number of bacteria from the genus Oscillibacter in their intestines had comparatively lower cholesterol levels in their stool and blood.

Pay attention to the right fatty acids

In additional laboratory experiments, the research group examined the Oscillibacter bacteria in more detail. She found that these absorb cholesterol and convert it into a substance called coprostanol, which is then further broken down by other bacteria. They also identified a gene for cholesterol conversion.

Further studies could contribute to the development of therapies that exploit the function of the intestinal microbiome, the researchers write. Measures that target microbial cholesterol metabolism in the intestine could potentially reduce cholesterol levels that are once too high.

Animal fats in particular, such as sausages, meat, butter and other dairy products, can lead to an increase in cholesterol concentrations in the blood. These fatty acids are also found in coconut oil, baked goods and high-fat sweets. Foods rich in cholesterol such as smoked fish, organ meats and egg yolks can also increase the level, but to a lesser extent. According to the Federal Center for Nutrition, unsaturated fatty acids, for example from the oils of plants and fish, are healthier.

msk/dpa