Medication May Build Up in Gut Bacteria, Impacting the Drug & Microbiome

Gut microbes are crucial to our health. They aid in the digestion of food and absorption of nutrients. But they can also interact with medications we take. While scientists have known that bacteria can alter some medications in a phenomenon known as biotransformation, this research has suggested that bacteria may be changing the effectiveness of drugs in significant ways since they can accumulate in the microbiome where they are not useful, or cause bacteria to produce moleucles that are different from the ones they would normally.

In a small model of a microbiome, in which a few types of bacteria were cultured together, the researchers found that the antidepressant duloxetine changed the balance of microbes. That antidepressant can bind to different metabolic enzymes in bacteria, so when it builds up in the microbes, the molecules that are typically generated by the bacteria change. Other microbes feed on those molecules, so the bacterial community as a whole is altered.

When the scientists gave bacteria that were exposed to duloxetine to a nematode worm model, the worms’ microbiome changed, as did their behavior, compared to worms not given duloxetine-exposed microbes.

Since this study used a microbiome model, more research will be necessary to confirm these findings in humans, the researchers acknowledged. It seems clear, however, that more attention needs to be paid to microbiome-drug interactions.