Study identifies gut bacteria that regulate cholesterol

A study published August 18 in Nature Microbiology found that certain species of bacteria in the gut interact with dietary cholesterol and use it to produce molecules that play important roles in human health. Generating helps keep cholesterol levels in balance.

Animals need adequate amounts of cholesterol to make bile, vitamin D, and hormones in their livers and to build healthy cell walls. However, too much cholesterol can cause arteries to build up and block, causing a heart attack or stroke.

This study is one of the first to identify a species of gut bacteria that converts cholesterol in animal foods into a molecule called cholesterol sulfate. Although more research is needed, early clues reveal that cholesterol sulfate functions as a signaling molecule in numerous biological pathways, including those involved in regulating infant health and development, immune cells and digestion. I am doing

The study also found that in mice, a subset of bacteria called Bacteroidetes help regulate cholesterol levels in the blood. affect lifelong health.

“This opens the door to thinking about whether the microbiome or specific microbes can be eliminated. Cholesterol out of circulation,” said Elizabeth Johnson. Assistant Professor of Molecular Nutrition, Agricultural Life Science. Postdoctoral researcher Henry Lee and his doctoral student Minting Lee, both in Johnson’s lab, are co-lead authors on the study.Characterizing the interaction of dietary cholesterol with the gut microbiota of mice and humans”

The discovery could lead to new treatments to replace the multi-billion dollar cholesterol-lowering drug industry. Potential treatments could include targeted diets, probiotics, or new drugs derived from molecules produced by these bacteria, all of which reduce many of the side effects associated with current drugs. may be reduced.

Cholesterol sulfate is readily produced in human tissues, but this study is the first to show that the gut microbiota can also produce cholesterol sulfate. This discovery was made possible by a new method called BOSSS (Bioorthogonal Label Sorted Array Spectroscopy) developed in Johnson’s lab. This was used to label dietary cholesterol with red fluorescence and track which bacteria interact with it. The system was then used to sequence the DNA of these bacteria and identify the species.

“The BOSSS technology allowed us to track which microorganisms were acting on cholesterol,” says Johnson. “Then I also took notes from chemistry to see which molecules were made and when.” [these bacteria] Interacts with cholesterol. ”

They found that Bacteroidetes produced cholesterol sulfate. Additionally, the researchers used germ-free mice inoculated with genetically engineered Bacteroidetes that lack the enzyme needed to convert cholesterol to cholesterol sulfate. This experiment revealed that the gut microbiota of these mice was incapable of producing cholesterol sulfate, whereas the microbiota of germ-free mice colonized with normal Bacteroidetes produced cholesterol sulfate.

“I think this research is very relevant to all parts of the lifecycle,” says Johnson. “In infants, how do lipids [fats, including cholesterol] Dietary protein is important for the production of microbiome-dependent molecules that influence development and for lifelong health. ”

Most cholesterol is made in the liver, but about one-fifth comes from animal foods. The findings are important for the importance of breast milk for providing adequate nutrition, and further research into cholesterol-deficient infant formulas, such as soy-based products, and whether they deprive infants of needed nutrients. has a meaning

In adults, saturated and trans fats in the diet can cause the liver to produce too much cholesterol, which can build up as plaque in the arteries.

“When we think about cholesterol metabolism and cardiovascular health, [there may be ways to] We use the microbiome to regulate cholesterol levels and other related lipids,” Johnson said.

Johnson’s lab has begun investigating which biological pathways require cholesterol sulfate to function properly.

This study was funded by the National Institutes of Health. biotechnology genomics facilityCornell Biotechnology Institute Resource Center Assists with Sequencing experiment.