Parkinson's add-on drugs may spur gut bacteria that break down levodopa, study finds

Levodopa—the gold-standard treatment for Parkinson's disease—increases dopamine in the brain. But as the disease progresses in severity, patients often need to take additional drugs to manage their symptoms. One class of drugs, called catechol-O-methyltransferase inhibitors (COMT-Is), can help increase the amount of levodopa that reaches the brain.