Age

18–75

Sex

ALL

Healthy volunteers

Not accepted

1\. Men or women, aged from 18 to 75 years old;
2\. Provide informed consent prior to enrolling in the study;
3\. Estimated glomerular filtration rate (eGFR) between 15-45 ml/min/1.73 m2 (calculated by CKD-EPI equation)

1\. Documented poorly controlled diabetes mellitus, poorly controlled hypertension, malignant tumour, or any clinically significant unstable medical condition;
2\. Active dysphagia or swallowing disorder; or a predisposition to or current bowel obstruction, ileus, or severe gastrointestinal motility disorders including severe constipation;
3\. Known hypersensitivity to sevelamer or any constituents of the study drug;
4\. Unable to comply with the requirements of the study;
5\. Hypophosphatemia (serum phosphorus level \<0.87mmol/L);
6\. Women who have a positive pregnancy test at enrollment or women who are breast-feeding;
7\. Have been enrolled in other interventional study;
8\. Received sevelamer or other intestinal adsorbents, or broad-spectrum antibiotic within one month prior to the screening period.

The Effect of Sevelamer Carbonate on Serum Trimethylamine-n-Oxide (TMAO) Level in Patients With Chronic Kidney Disease (CKD) Stage 3b-4