Abstract: Objective To investigate the effect of TP53-induced glycolysis and apoptosis regulator (TIGAR) gene deletion on dextran sulfate sodium (DSS)-induced colitis in mice and its potential mechanisms. Methods C57BL/6 background TIGAR knockout (TIGAR-KO) mice and wild-type (WT) mice were treated with 3% DSS for 8 days to establish an acute colitis model. Body weight changes were monitored daily, and colonic shortening was evaluated. Colonic tissues were analyzed histologically by Hematoxylin-Eosin (H-E) staining and Periodic Acid-Schiff (PAS) staining. Differentially expressed genes were analyzed through RNA sequencing (RNA-seq), and gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed. Real-time fluorescence quantitative PCR (RT-PCR) was used to validate RNA-seq results. Results After DSS treatment, TIGAR knockout mice exhibited more significant weight loss, higher disease activity index (DAI) scores, more severe colonic shortening, and higher mortality than TIGAR-KO mice. According to H-E staining results, TIGAR knockout mice presented extensive damage to the colonic mucosal crypt structure, deep ulcer formation, and dense neutrophil infiltration. PAS staining showed a sharp reduction in the number of goblet cells, significantly impairing mucus secretion. KEGG analysis indicated that the Ras signaling pathway, MAPK signaling pathway, and inflammatory bowel disease pathway were significantly enriched in the TIGAR-KO group, suggesting that TIGAR deficiency exacerbates intestinal inflammation and mucosal immune imbalance through the activation of the Ras-MAPK signaling cascade. GO enrichment analysis further showed that TIGAR knockout affects biological processes related to stimulus response, protein complex composition in cellular components, and catalytic activity and binding ability in molecular functions, supporting its role in oxidative stress and metabolic regulation. Compared with the TIGAR-KO group, the TIGAR-KO+DSS group showed significant increases in mRNA levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and extracellular-regulated kinase 1 (ERK1), as well as decreases in tight junction protein 1 (Claudin-1) mRNA levels. Conclusions TIGAR gene deletion exacerbates DSS-induced colitis in mice, and its protective role may be related to the inhibition of excessive inflammatory responses and the maintenance of intestinal mucosal barrier function. This study provides a new target for the treatment of inflammatory bowel disease (IBD).