Effect of Probiotics on Immunosuppressant Therapy in Kidney Transplant Recipients

People who receive a donor kidney must take drugs to prevent their bodies from attacking the new organ. These drugs are called immunosuppressants. Probiotics are beneficial microbes that support gut health. They are often given to reduce immunosuppressant toxicity for the gut. The goal of this clinical trial is to learn if probiotics change the levels of immunosuppressants in the blood in patients who have received a kidney transplant. The main question it aims to answer is: • Does a short-term treatment with a probiotic mixture change the circulating levels of the immunosuppressant drugs cyclosporine A, tacrolimus, sirolimus, everolimus, mycophenolic acid, mycophenolate mofetil, and prednisolone? In addition, researchers will also see if probiotics reduce systemic inflammation or ameliorate renal function. Study participants will be patients with kidney transplant. At different times, each participant will take either probiotics or look-alike capsules with no probiotics. Researchers will compare the levels of immunosuppressant in the blood when participants take the probiotics with those when they take the capsules with no microbes. Study participants will have to: * Take oral capsules containing a probiotc mixture for one month and look-alike capsules with no probiotics for another month with a one-month interval between these two treatments; * Go to the hospital every 30 days for three months for the collection of blood samples; * Collect feces specimens for microbiome analysis every 30 days for three months and bring them to the hospital.