Bile salt hydrolase catalyses formation of amine-conjugated bile acids. (https://pubmed.ncbi.nlm.nih.gov/38326609/)

These scientists wanted to understand how bacteria in our stomachs can affect our bodies. They knew that these bacteria make something called amino acid bile acid amidates, but they didn't know which gene in the bacteria was responsible for making it. So, they did some experiments to find out.

First, they discovered that a gene called bile salt hydrolase (BSH) has two jobs. One job is to help break down bile acids, which are important for digestion. But the scientists also found out that BSH can do something else - it can combine amino acids with bile acids to make amino acid bile acid amidates.

To study this process, the scientists used different techniques. They used special chemicals to block the activity of BSH, and they also put the BSH gene into other bacteria to see what would happen. They even made some bacteria without the BSH gene to compare them with the normal bacteria.

Next, the scientists looked at samples from babies to see if the amount of amino acid bile acid amidates was related to the bacteria in their stomachs. And guess what? They found that the more bacteria had the BSH gene, the more amino acid bile acid amidates were made.

Finally, the scientists wanted to know what these amino acid bile acid amidates do to our bodies. They tested them on cells in a dish and found out that they can activate certain proteins in our bodies called transcription factors. These proteins help control how our bodies work.

So, these scientists discovered that bacteria in our stomachs can make amino acid bile acid amidates using a gene called BSH. This helps us understand how these bacteria can affect our bodies and how our bodies use bile acids.

Rimal B., Collins SL., Tanes CE., Rocha ER., Granda MA., Solanki S., Hoque NJ., Gentry EC., Koo I., Reilly ER., Hao F., Paudel D., Singh V., Yan T., Kim MS., Bittinger K., Zackular JP., Krausz KW., Desai D., Amin S., Coleman JP., Shah YM., Bisanz JE., Gonzalez FJ., Vanden Heuvel JP., Wu GD., Zemel BS., Dorrestein PC., Weinert EE., Patterson AD. Bile salt hydrolase catalyses formation of amine-conjugated bile acids. Nature. 2024 Feb 7. doi: 10.1038/s41586-023-06990-w.