TH and Parkinson disease: Consistent with the behavioral results, FMT from PD patients led to a further loss of TH+ fibers in the striatum (the MPTP + PD FMT group vs. the MPTP group, P < 0.05, Fig. 2B) and TH+ somata in the SNc (the MPTP + PD FMT group vs. the MPTP group, P < 0.0001, Fig. 2D).