BUN: blood urea nitrogen; CKD: chronic kidney disease; eGFR: estimated glomerular filtration rate; GSH: glutathione; hsCRP: high sensitivity C-reactive protein; IAA: indole-3-acetic acid; IL-6: interleukin 6; IS: 3-indoxyl sulfate; MDA: malondialdehyde; NO: nitric oxide; PCS: p-cresol sulphate; QoL: quality of life; SD: standard deviation; SF-8: short form-8 health survey; TNF- α: tumor necrosis factor -alpha. Here, TNF is linked to chronic kidney disease.