Bile salt hydrolase acyltransferase activity expands bile acid diversity. (https://pubmed.ncbi.nlm.nih.gov/38326608/)

These scientists wanted to understand more about a substance called bile acids, which are found in our bodies and help us digest fats and absorb vitamins. They discovered that there is an enzyme called bile salt hydrolase/transferase (BSH/T) that can change the bile acids by adding different amino acids to them. This process creates a new group of substances called microbially conjugated bile acids (MCBAs).

The scientists found that a type of bacteria called Clostridium perfringens has the ability to perform this transformation very quickly. They also discovered that other types of bacteria in our gut can do this too, but each bacteria has its own specific way of adding amino acids to the bile acids.

The scientists also found that the structure of the BSH/T enzyme affects which amino acids can be added to the bile acids. They did experiments where they changed the structure of the enzyme and saw how it affected the process.

They also discovered that these new MCBAs have antimicrobial properties, which means they can help fight against harmful bacteria. When they tested the MCBAs in mice, they found that the MCBAs were able to enter the liver and gallbladder and their levels in the gut were affected by changes in the gut caused by bariatric surgery.

Finally, the scientists measured the levels of MCBAs in human fecal samples and found that they were present in similar amounts as the original bile acids. They also found that the levels of MCBAs decreased after bariatric surgery, suggesting that changes in our gut can affect the levels of these substances.

In conclusion, the scientists discovered that the BSH/T enzyme can change the bile acids in our bodies, creating a new group of substances called MCBAs. These MCBAs have antimicrobial properties and can be found in our gut at similar levels as the original bile acids. The scientists believe that these MCBAs could have an impact on our gut bacteria and our overall health.

Guzior DV., Okros M., Shivel M., Armwald B., Bridges C., Fu Y., Martin C., Schilmiller AL., Miller WM., Ziegler KM., Sims MD., Maddens ME., Graham SF., Hausinger RP., Quinn RA. Bile salt hydrolase acyltransferase activity expands bile acid diversity. Nature. 2024 Feb 7. doi: 10.1038/s41586-024-07017-8.