TLR4 and Hepatic fibrosis: Lipopolysaccharide (LPS), the main component of endotoxin, can activate intracellular signal transduction by the use of toll-like receptor 4 (TLR4) in the liver, thus exacerbating liver inflammation, and promoting the progression of liver fibrosis, which is the “gut-liver” axis (Seki et al., 2007; Szabo, 2015; Tilg et al., 2020; Mandato et al., 2021; Rao et al., 2021; T Wang et al., 2022).