N5_data_original

we investigated the therapeutic potential of Lactobacillus johnsonii N5 in a murine dextran sulfate sodium (DSS)-induced colitis model. Prophylactic N5 administration alleviated colitis symptoms, reduced fecal and serum lipocalin-2 levels, and suppressed colonic pro-inflammatory cytokines. N5 preserved microbial diversity, enhanced mucus secretion, and reinforced mucosal barrier integrity, preventing colitis onset. Therapeutically, N5 attenuated disease progression by downregulating IL-1β, IL-6, IL-8 expression, restoring Lactobacillus populations, and suppressing Escherichia-Shigella expansion, thereby reducing bacterial translocation and systemic inflammation.