highly significantP = 4.7 × 10 −3
Notably, all GBA-NMC individuals who were identified as prodromal PD, based on the MDS research criteria 16 , had the abundance of coherent PD-enriched species above the median, a highly significant bias ( χ 2 test, P = 4.7 × 10 −3 ), and four were at the very top of the distribution (Fig. 3 ; P = 5.7 × 10 −4 ).