The Regulatory Effect of Human Umbilical Cord Mesenchymal Stem Cells on the Gut Microbiota in Diabetic Nephropathy Rats.

BACKGROUND

Chronic inflammation is increasingly recognized as a key factor in the progression of diabetic kidney disease (DKD). By discovering that the regulation of gut microbiota plays an important role in diabetic kidney disease, human umbilical cord mesenchymal stem cells (HU-MSCs) explore the mechanism of fibrosis in diabetic kidney disease through the regulation of chronic inflammation, providing new clinical insights for the prediction, diagnosis, and treatment of diabetic kidney disease.

OBJECTIVES

This study explores the regulatory effects of HU-MSCs on gut microbiota and their protective role on the intestinal barrier in diabetic nephropathy rats.

MATERIAL AND METHOD

Diabetic kidney disease (DKD) was induced in SD rats via intraperitoneal injection of streptozotocin. Three groups were established: control group, diabetic kidney disease (DKD) group, and treatment group (DKD+HU-MSCs) (10 rats each). After diabetic kidney disease (DKD) modeling, rats in the treatment group (DKD+HU-MSCs) received 2×10 HU-MSCs via tail vein injection weekly for four weeks. Blood, urine, kidney, and colon tissues were collected post-treatment. Pathological changes were observed microscopically; immunohistochemistry detected tight junction proteins ZO-1 and Occludin in colon tissues. DiR-labeled HU-MSCs distribution was assessed with imaging, and immunohistochemistry evaluated human mesenchymal stem cell markers CD44 and CD90. Fecal samples underwent metagenomic sequencing for gut microbiota analysis.

RESULTS

HU-MSCs transplantation significantly reduced Blood Urea Nitrogen (BUN), Serum Creatinine (SCr), and 24-hour urinary protein levels (all P < 0.05) and improved renal pathology. Markers CD44 and CD90 were present in DKD rat colon tissues. Tight junction proteins Occludin and ZO-1 were decreased in DKD rats but increased following HU-MSCs treatment. Metagenomic analysis showed enhanced abundance of beneficial bacteria (Bifidobacterium and Lactobacillus) with HU-MSCs. Urinary protein was positively correlated with Prevotella and negatively with Ligilactobacillus (p < 0.05).

CONCLUSIONS

HU-MSCs may improve intestinal barrier function in diabetic kidney disease (DKD) rats by restoring gut microbiota structure and increasing intestinal tight junction proteins, offering a potential pathway for enhancing renal function.