Gut bacteria can alter how well a medication works
A healthy human gut microbiome is made up of over 1,000 species of bacteria that work to help break down food and keep the digestive system in functioning order.
Bacteria are an essential part of overall good health.
However, researchers at the University of California, San Francisco have found that sometimes, gut bacteria can interfere with the way a certain medication is supposed to work.
“[T]his kind of microbial metabolism can also be detrimental,” says Vayu Maini Rekdal, a graduate student in the laboratory of first study author Prof. Emily Balskus. Their paper now appears in the journal Science.
“Maybe the drug is not going to reach its target in the body, maybe it’s going to be toxic all of a sudden, maybe it’s going to be less helpful,” adds Maini Rekdal.
Solving the microbial puzzle
First, the researchers looked at the digestive enzymes that convert L-dopa into dopamine, noting there are only a few that can do this.
Using the Human Microbiome Project, the researchers sought bacteria that had the genes necessary to do the same thing; and in this research, they uncovered that there is only one specific bacterium that consumes the L-dopa. It is called Enterococcus faecalis.
This presented a new problem to solve, as the introduction of the other medication (carbidopa) is meant to stop this reaction — but it does not always work the way it is supposed to do.
Although researchers do not yet know why this occurs, they suggest that the two types of enzyme (human and bacterial) might not work in the same ways because they are slightly different.
The new study, however, has already resulted in at least one positive finding; the researchers have found a specific molecule that can inhibit the bacteria without completely destroying them.
“The molecule turns off this unwanted bacterial metabolism without killing the bacteria; it’s just targeting a nonessential enzyme,” says Maini Rekdal.