Furthermore, when subjected to ConA injection, mice receiving gut microbiota transplantation from patients with MDD exhibited more severe liver damage than those harboring control microbiota (Figure S4A), as evidenced by elevated serum levels of ALT and AST (Figure S4B) and hepatic expression of NLRP3 (Figure 4B and Figure S4C). The gene discussed is NLRP3; the disease is major depressive disorder.