Corrigendum: Gut–Brain Axis: Potential Factors Involved in the Pathogenesis of Parkinson's Disease - Chao, Yin-Xia; Gulam, Muhammad Yaaseen; Chia, Nicholas Shyh Jenn; Feng, Lei; Rotzschke, Olaf; Tan, Eng-King (Frontiers in Neurology, 2020)