Antioxidant and Immunomodulatory Effects of Lactobacillus plantarum ZS62 in a Mouse Model of Colitis

Lactobacillus plantarum belongs to the genus Lactobacillus, which is the largest genus of lactic acid bacteria. Previous research revealed that L. plantarum ZS62 has a protective effect on the stomach, and the stomach and intestine are often considered to be two inseparable organs that ensure the normal function of the gut. In this study, a dextran sulfate sodium (DSS)-induced inflammatory bowel disease (IBD) mouse model was established to investigate the preventive effect of Lactobacillus plantarum ZS62 against IBD, with a focus on its modulatory roles in oxidative stress and immune responses. The alleviative effect of this strain on IBD was evaluated by assessing colon length, histopathological alterations, serum antioxidant capacity, inflammatory cytokine levels, as well as mRNA and protein expression of relevant genes in colon tissues. The results demonstrated that L. plantarum ZS62 significantly alleviated colon shortening and reduced histological damage in IBD mice. It downregulated serum levels of malondialdehyde (MDA), myeloperoxidase (MPO), interleukin-1β (IL-1β), IL-6, IL-12, tumour necrosis factor-α (TNF-α), and interferon-γ (IFN-γ), and decreased the relative mRNA and protein expression of IL-1β, IL-12, TNF-α, cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and nuclear factor-κB p65 (NF-κB p65) in colon tissues. Conversely, L. plantarum ZS62 upregulated serum levels of catalase (CAT), total superoxide dismutase (T-SOD), and IL-10, and enhanced the expression of copper/zinc superoxide dismutase (Cu/Zn SOD), manganese superoxide dismutase (Mn SOD), glutathione peroxidase (GSH-Px), CAT, IL-10, and inhibitor of κB-α (IκB-α) at both transcriptional and protein levels in the colon. In summary, Lactobacillus plantarum ZS62 exerted a notable preventive effect against DSS-induced IBD by modulating oxidative stress and inflammatory pathways, highlighting its potential as a probiotic candidate for intestinal health management.