TNF and central nervous system disorder: Interestingly, accumulating studies have shown that TMAO accelerates the progression of many inflammatory diseases, including cardiovascular disease, CKD, and central nervous system disease, by activating inflammatory pathways, such as the MAPK, NF-κB, and NLRP3 signaling pathways, and then increasing pro-inflammatory molecules, including tumor necrosis factor alpha, IL-6, IL-1β, and IL-18 (Seldin et al., 2016; Sun et al., 2017; Geng et al., 2018; Zhang et al., 2019, 2020).