TLR4 and Parkinson disease: Sun et al. gavaged mptp-induced Parkinson’s disease mice with 200 μL of cecal bacterial suspension in healthy mice for 7 days, which, by decreasing the TLR4/TBK1/NF-jB/TNFa signaling pathway in both the intestine and brain activity and reduced brain glial cell activation (Sun et al., 2018).