Abstract:[Objective] This study aims to investigate the reparative effect of L-arabinose on the intestinal mucosal barrier and its blood glucose-lowering mechanism in the rat model of type 2 diabetes mellitus (T2DM). [Method] A rat model of T2DM was established via streptozotocin (STZ) combined with a high-fat diet. The successfully modeled rats were randomly assigned to a model control group and low-, medium-, and high-dose L-arabinose intervention groups. After 28 d of continuous intervention by gavage, parameters including fasting blood glucose level, blood lipids level, serum inflammatory factors levels, expression of tight junction proteins in the intestinal tissue, histomorphology, and mass fractions of short-chain fatty acids (SCFAs) in the cecal tissue were measured. [Result] L-Arabinose significantly improved glycolipid metabolism in diabetic rats and repaired the intestinal mucosal barrier by promoting SCFA production: it up-regulated the expression of tight junction proteins (occludin and claudin-1, P<0.05) in the jejunum, restored villus structure, increased mucus secretion, and reduced serum levels of pro-inflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) (P<0.05). The regulatory effects of L-arabinose on individual SCFAs components and inflammatory factors varied among doses. [Conclusion] L-Arabinose can repair the intestinal mucosal barrier by regulating SCFAs metabolism, inhibit inflammatory responses, and ameliorate glycolipid metabolic disorders in diabetic rats. The findings provide a theoretical basis for the development of functional foods for T2DM.