In experimental colitis models, L. johnsonii reduced pro-inflammatory cytokines (interleukin-1 beta—IL-1β, IL-6, TNF-α, C-X-C motif chemokine ligand 1—CXCL1) while elevating IL-10, and restored the regulatory T cell (Treg)/T helper 17 (Th17) balance, underscoring its capacity to modulate both innate and adaptive immunity [20]. The gene discussed is CXCL1; the disease is colitis.