CD4+ cells, CD4+ TCM cells, CD8+ TCM cells, and the CD4+/CD8+ cell ratio were significantly higher in the DKD group than in the HC group, as were levels of pro‐inflammatory mediators, including IL‐6, TNF‐α, and sCD14, and expression of the gut barrier dysfunction marker ZO‐1. Here, TNF is linked to diabetic kidney disease.