Inadequate Production of H2 by Gut Microbiota and Parkinson Disease

Dysbiosis of the gut flora accompanies Parkinson disease (PD), yet no specific cause–effect link has been identified so far. The gut microbiota produce molecular hydrogen (H2), a ubiquitous molecule recently recognized as a biologically active gas with antioxidant, antiapoptotic, anti-inflammatory, cytoprotective, and signaling properties. Here, we discuss an idea that an impaired production of endogenous H2 by intestinal microbiota might play a role in PD pathogenesis, with supplemental H2 debated as a possible therapy for this progressive neurodegenerative disease.