Bivalent gambogic acid-functionalized curcumin nanoparticles with insulin modulate the gut-liver-kidney network in type 2 diabetes.

The gut-liver-kidney (GLK) network is a critical driver of type 2 diabetes mellitus (T2DM) complications, where gut dysbiosis triggers cycle of hepatic metabolic stress and subsequent renal dysfunction through a complex, bidirectional signaling crosstalk. Despite its importance, therapeutic strategies capable of addressing this multi-organ crosstalk remain elusive. Here, we demonstrate that bivalent functionalized curcumin-encapsulating PLGA nanoparticles (nGA2-CUR) combined with subcutaneous insulin beneficially modulate the GLK network in obese T2DM mice. This combination therapy successfully stabilized systemic glucose homeostasis and restored essential endocrine signaling (insulin, GLP-1, and GIP) while significantly suppressing pro-inflammatory markers (MCP-1, haptoglobin). Microbiome profiling revealed a suppression of pathobionts alongside distinct sex-specific restorative responses, where males exhibited Muribaculaceae enrichment while females showed Bifidobacterium expansion. Integrated liver metabolomics associated these microbial shifts with unique organ-specific repair responses in each sex. Males showed elevated levels of purine salvage pathway intermediates alongside suppression of a specific pathobiont cluster (including Lautropia and Porphyromonas) correlated with oxidative stress, whereas females replenished aromatic amino acids, consistent with reduced predicted microbial proteolytic potential and lower markers of nephrotoxic uremic toxin production. Molecular analysis confirmed the downregulation of glucose-sensitive pathways (Chrebp/Srebp-1c). These systemic improvements were accompanied by an anti-inflammatory M2 macrophage profile shift, alongside suppression of renal fibrosis via the TGFβ/SMAD network and reduced injury markers (Cystatin C and Osteopontin). Our findings suggest that by reshaping the gut microbiome to alleviate upstream hepatic metabolic burden, this nanoparticle-enhanced therapy provides a sex-specific framework for attenuating irreversible diabetic renal injury.