IFNL1 and colitis: The early representative study treated colitis mice with engineered L. lactis‐secreting IL‐10, finding that in situ generation of engineered bacteria can lower the therapeutic dose of IL‐10.[26] In recent years, researchers have attempted to produce other anti‐inflammatory cytokines such as IL‐27,[46] IL‐35,[47] and interferon lambda 1 (IFNL1 or IL‐29)[48] by modified bacteria (Figure 2).