Further, Castelli et al. investigated the effects of the probiotic formulation SLAB51 on the SH-SY5Y cell model of PD finding a reduction in dopaminergic neuronal loss in the SN and striatum; this effect was associated with a rise in the activation of the neuroprotective and neuronal survival BDNF pathway, a reduction in the neuronal death pathway, and a significant decrease in 4-hydroxynonenal protein adducts level, suggesting its potential antioxidant property [331]. Here, BDNF is linked to Parkinson disease.