Trillions of microbes live in our gut to help break down and absorb nutrients. Since our guts cannot digest certain substances like fiber, the microbes step up to perform this task.
“But this kind of microbial metabolism can also be detrimental.” said Maini Rekdal, a graduate student in the lab of Professor Emily Balskus. Gut microbes can chew up medications too, and often with hazardous side effects. “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.”
Microbiome can interfere with a drug’s intended path through the body. Considering Levodopa (L-dopa), the primary treatment for Parkinson’s disease, they have identified which bacteria out of the trillions of species is responsible for degrading the drug and how to stop it from interfering.
Only about 1% – 5% of the drug actually reaches the brain. Since the late 1960s researchers have known that the body’s enzymes break down L-dopa in the gut, preventing the drug from reaching the brain. Carbidopa was added to block the breakdown so that it could make it to the brain.
However, there is still a huge variance problem. Not only is the drug less effective for some patients, but when L-dopa is transformed into dopamine outside of the brain, the compound can cause side effects, including severe gastrointestinal distress and cardiac arrhythmias. If less of the drug reaches the brain then patients are often given more to manage their symptoms, potentially exacerbating these side effects.
Previous research showed that antibiotics improved a patient’s response to L-dopa, and scientists speculated that bacteria might be to blame. Still, no one identified which bacterial species might be culpable, or how and why they eat the drug.
Great news! Balskus’ team launched an investigation and have identified a compound that inhibits the drug breakdown in the gut and increases L-dopa bioavailability in mice. Now further research is needed in human bodies. Hopefully through this research they will learn more about our complex gut chemistry. This research is a huge breakthrough and could make L-dopa much more effective with consistent outcomes.
Want to read the down and dirty research about the process? Here’s a link to the article.
Source:
Harvard
Caitlin McDermott-Murphy – Harvard
Original Research:
Open access
“Discovery and inhibition of an interspecies gut bacterial pathway for Levodopa metabolism”. Vayu Maini Rekdal, Elizabeth N. Bess, Jordan E. Bisanz, Peter J. Turnbaugh, Emily P. Balskus.
Science. doi:10.1126/science.aau6323