The goal of this clinical trial is to learn if Coated Aldehyde Oxystarch (Xiqing) works to reduce protein-bound uremic toxins (PBUTs) in adults with end-stage renal disease (ESRD). It will also learn about the safety of Coated Aldehyde Oxystarch. The main questions it aims to answer are:

Does Coated Aldehyde Oxystarch lower the blood levels of protein-bound uremic toxins, such as indoxyl sulfate and p-cresyl sulfate?

What medical problems do participants have when taking Coated Aldehyde Oxystarch?

Researchers will compare the levels of PBUTs before treatment (baseline) with those after treatment with Coated Aldehyde Oxystarch to see if it works to reduce these toxins.

Participants will:

Take Coated Aldehyde Oxystarch (Xiqing) 10 capsules per time, three times daily (each capsule 0.625 g, total daily dose 18.75 g) for 3 months.

Visit the clinic every month for checkups and blood tests.

Provide blood samples to measure protein-bound uremic toxin levels and routine safety parameters.

Patients with end-stage renal disease (ESRD) have high morbidity and mortality. Current dialysis poorly clears protein-bound uremic toxins (PBUTs) such as indoxyl sulfate (IS), which is associated with adverse outcomes. Coated Aldehyde Oxystarch is an oral adsorbent that binds IS in vitro, but its in vivo effect is unknown. This study aims to rigorously explore the effect of Coated Aldehyde Oxystarch on reducing serum IS and other PBUTs in maintenance hemodialysis patients. This is the first in vivo study to evaluate the effect of Coated Aldehyde Oxystarch on reducing protein-bound uremic toxins (particularly indoxyl sulfate) in patients with end-stage renal disease, offering a novel intestinal-targeted strategy to mitigate toxin accumulation in dialysis patients.

Inclusion Criteria:

• Age ≥ 18 years, no restriction on sex or ethnicity.
• Receiving maintenance dialysis for at least 3 months, with dialysis regimen remaining unchanged during the trial period.
• If taking other medications that do not interfere with gut microbiota prior to enrollment, they must have been stable for at least 1 month and the regimen must remain unchanged during the trial.
• Ability to understand and voluntarily sign the informed consent form.

Exclusion Criteria:

• Known allergy to Coated Aldehyde Oxystarch.
• History of or planned kidney transplantation within 6 months, or change in dialysis regimen.
• Use of medications or supplements that may affect gut microbiota (e.g., antibiotics, probiotics, prebiotics, laxatives) within the past 3 months.
• Diagnosis of serious gastrointestinal diseases, including gastrointestinal bleeding, colitis, inflammatory bowel disease, irritable bowel syndrome, history of intestinal obstruction, history of gastrectomy or duodenectomy.
• History of cardiovascular or cerebrovascular events within 3 months prior to screening, including hospitalization for stroke, myocardial infarction, unstable angina, congestive heart failure; severe valvular stenosis, uncontrolled atrial fibrillation or arrhythmia; QTc interval >500 ms on repeated ECG.
• Concurrent severe primary diseases of cardiovascular, cerebrovascular, hepatic, hematopoietic systems, or other known life-threatening diseases (e.g., malignancy, AIDS), or patients with mental or legal disabilities.
• Investigator judges life expectancy ≤6 months.
• Inability to maintain stable dietary habits during the study period.
• Inability to maintain original dialysis regimen during the study period.
• Use of Chinese patent medicines for kidney disease (e.g., Shenkang Injection, Haikun Shenxi Capsule, Shenshuaining, Tripterygium preparations, Niaoduqing Granules) within 1 month prior to enrollment.
• Participation in another clinical trial within the past 1 month.
• Intellectual disability, psychiatric disorders, or suspected/confirmed history of alcohol or drug abuse that may affect compliance.
• Any other condition that, in the investigator's judgment, makes the patient unsuitable for participation in this study.