SNCA and Parkinson disease: In another study that used metagenomic, metatranscriptomic, metaproteomic, and metabolic data to explore the functional attributes of the microbiome that influence Parkinson’s disease (PD) pathogenesis, a preliminary result found the metabolite 2-hydroxypyridine (2-HP) and the microbe Methanobrevibacter smithii to be enriched in PD, prompting several experiments which verified their effects on alpha synuclein aggregation (Wilmes et al., 2022).