It is a well-known fact that a broad range of drugs can affect gut microbiota composition. Furthermore, the gut microbiome may affect drug efficacy and toxicity—previous findings have suggested that gut microbes could shape benefits from cancer immunotherapy—thus contributing to the explanation of why not all patients respond in the same way to the same medication. However, little is known about the quantitative contribution of the host and the gut microbiome to drug metabolism.

A new study, led by Dr. Andrew Goodman from the Yale University School of Medicine (New Haven, USA), provides some clues about how the gut microbiome influences the host’s ability to metabolize medical drugs by using an experimental and computational methodology.

The researchers studied, both in vitro and in vivo, the effects of gut bacteria on the metabolism of two antiviral drugs—brivudine and sorivudine—and of benzodiazepine clonazepam. The study finds that the gut microbiota of the host is an important contributor to the circulating toxic metabolites of certain drugs such as the antivirals brivudine and the anti-anxiety drug clonazapem. These findings are a step forward in understanding which drugs should be administered to a patient to minimize their toxic side effects and also open the option of manipulating the intestinal microbiome to achieve a better therapeutic response.

Read more: Gut Microbiota for Health