Exopolysaccharides (EPS) have attracted attention due to their potential role in intestinal repair and stabilization of gut microorganisms. This study aims to investigate the influences of EPS (GEPS) produced by Pediococcus pentosaceus LL-07 on dextran sodium sulfate (DSS)-induced colitis and to reveal the underlying mechanisms. Results showed that GEPS intervention significantly reduced weight loss and colon length shortening in colitis mice, and suppressed the expression of inflammation-related enzymes (myeloperoxidase (MPO), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS)), and pro-inflammatory cytokines (interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and interleukin 1β (IL-1β)). The anti-inflammatory factor interleukin 10 (IL-10), malondialdehyde, and peroxidation stress factors (catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px)), were increased. The tight junction proteins (occludin, Claudin-3, and ZO-1) associated with the intestinal barrier were also increased. The gut microbiota was significantly improved, with an increase in the beneficial bacteria (Ligilactobacillus, Lactobacillus, Alloprevotella, etc.) and a decrease in the harmful bacteria (Escherichia_Shigella, etc.). In conclusion, GEPS can improve DSS-induced colitis by inhibiting inflammatory responses, maintaining the intestinal barrier, and regulating the balance of the gut microbiota. These results help accelerate the development of GEPS as a new agent for the treatment of colitis.