IL6 and Parkinson disease: In contrast, we found that pro-inflammatory cytokines (i.e., IL-1β, IL-6 and TNF-α) were significantly increased in plasma and the anti-inflammatory cytokine IL-10 was reduced along with an increased concentration of circulating LPS and reduced concentrations of the gut microbial SCFA metabolites butyrate and propionate, considered (at least experimentally) as neuroprotective in other PD models (Ostendorf et al., 2020; Hou Y. et al., 2021; Hou Y. F. et al., 2021).