Polysaccharide from Gleditsia sinensis Seed Endosperm Ameliorates Type 2 Diabetes and Its Associated Cardiorenal Injuries by Modulating TLR4/MyD88/NF-κB Pathway and Gut Microbiota

Background: Type 2 diabetes mellitus (T2DM) represents a pressing global health challenge, underscoring the urgency of developing effective dietary interventions derived from natural resources. Zaojiaomi polysaccharide (ZJMP) from the endosperm of Gleditsia sinensis seeds (zaojiaomi), a traditional edible product, exhibits largely underexplored potential in T2DM management. Methods: In the present study, the antidiabetic effects and underlying mechanisms of ZJMP were investigated using a rat model of T2DM induced by a high-fat diet (HFD) combined with streptozotocin (STZ). Relevant biochemical indicators were detected, and histopathological examination was performed. The expression levels of key components of the TLR4/MyD88/NF-κB signaling pathway, as well as the inflammatory cytokines IL-6 and IL-1β in renal tissues, were further analyzed. Additionally, gut microbiota composition and the levels of short-chain fatty acids were determined. Results: ZJMP treatment significantly ameliorated hyperglycemia and dyslipidemia, elevated serum insulin levels, reduced intestinal mucosal permeability, and attenuated histopathological lesions in the heart, kidney, and pancreas of T2DM rats. Meanwhile, ZJMP notably alleviated renal inflammation by suppressing the production of IL-1β and IL-6, as well as inhibiting the TLR4/MyD88/NF-κB pathway. Furthermore, ZJMP administration effectively modulated gut microbiota composition and increased fecal concentrations of acetic acid and propionic acid. Conclusions: Collectively, these findings elucidate the novel bioactivity of ZJMP and highlight its potential as a promising functional food ingredient or dietary supplement for T2DM management.