Changes in the intestinal flora have a major influence on various diseases. It has now been found that certain microbes of the intestinal flora reduce cholesterol in the intestine and thus significantly reduce cholesterol levels and the risk of cardiovascular diseases.
In a new study involving experts from Harvard Medical School, the role of intestinal flora in cardiovascular disease was examined in detail. The results can be read in the English-language specialist journal “Cell”.
Influence of intestinal flora on health
The intestinal flora not only influences general health, but can also increase the risk of various serious diseases such as type 2 diabetes, obesity and inflammatory bowel disease, the researchers report.
Conversely, the intestinal flora can also significantly reduce the risk of cardiovascular disease by using certain types of bacteria in the intestine to utilize cholesterol and thus lower cholesterol levels, the team adds.
The experts came to this conclusion by analyzing the metabolites and microbial genomes of more than 1,400 participants in the Framingham Heart Study.
Certain bacteria lower cholesterol
It was shown that Oscillibacter bacteria absorb and metabolize cholesterol. Additionally, it was found that people with increased levels of these bacteria in their gut had lower cholesterol levels.
In addition, the team managed to identify a mechanism that the bacteria likely use to break down cholesterol.
According to the experts, the new findings suggest that targeted influence on the intestinal flora could help reduce cholesterol levels in humans in the future. This lays the foundation for more targeted research into how changes in the intestinal flora affect health and diseases.
16,000 associations identified
“Our research combines findings from human subjects with experimental validation to ensure that we achieve actionable mechanistic insights that can serve as a starting point for improving cardiovascular health,” explains study author Professor Ramnik J. Xavier in a press release.
In total, more than 16,000 associations between microbes and metabolic traits were identified, according to the team. A particularly strong association was found between several bacterial species of the genus Oscillibacter and lower cholesterol levels.
How do intestinal bacteria break down cholesterol?
The experts examined which biochemical pathway the microbes use to break down cholesterol. To do this, microbes of the genus Oscillibacter were first bred in the laboratory.
Mass spectrometry was then used to identify the most likely byproducts of cholesterol metabolism in the bacteria. The team explains that this ultimately made it possible to determine how the bacteria lower cholesterol levels.
According to the researchers, this is because the bacteria convert cholesterol into intermediate products, which can then be broken down by other bacteria and excreted from the body.
With the help of machine learning, it was possible to identify the enzymes responsible for this biochemical conversion. These enzymes could also be detected in the laboratory in the degradation products of cholesterol and specifically in certain Oscillibacter bacteria, the experts add.
Eubacterium coprostanoligenes also lowers cholesterol
In addition, the researchers were able to identify another genus of intestinal bacteria called Eubacterium coprostanoligenes, which also helps reduce cholesterol levels. In the new research, the team also found that Eubacterium may have a synergistic effect with Oscillibacter on cholesterol levels.
According to the researchers, this suggests that studying combinations of bacterial species could help significantly improve our understanding of how different microbial communities interact and influence human health.
The results of the new study identifying cholesterol-degrading enzymes will pave the way for the discovery of other similar metabolic pathways influenced by gut microbes in the future that could be targeted therapeutically, the research team hopes. (as)
