The dope on L-dopa metabolism

Microbiota The efficacy of l-dopa treatment for Parkinson's disease is hugely variable between individuals, depending on the composition of their microbiota. l-Dopa is decarboxylated into active dopamine, but if the gut microbiota metabolize l-dopa before it crosses the blood-brain barrier, medication is ineffective. Maini Rekdal et al. found that different species of bacterium are involved in l-dopa metabolism (see the Perspective by O'Neill). Tyrosine decarboxylase (TDC) from Enterococcus faecalis and dopamine dehydroxylase (Dadh) from Eggerthella lenta A2 sequentially metabolized l-dopa into m -tyramine. The microbial l-dopa decarboxylase can be inactivated by ( S )-α-fluoromethyltyrosine (AFMT), which indicates possibilities for developing combinations of Parkinson's drugs to circumvent microbial inactivation. Science , this issue p. [eaau6323][1]; see also p. [1030][2] [1]: /lookup/doi/10.1126/science.aau6323 [2]: /lookup/doi/10.1126/science.aax8937