Chronic kidney disease (CKD) is a progressive disease with hidden epidemics and one of the most significant contributing factors to end-stage renal disease (ESRD), cardiovascular comorbidities, cachexia and anemia, which accounts for a nearly 1.2 million populations died per year.

Inclusion Criteria:

Age-matched and gender-matched HC with normal renal and liver function and not taking any medications were enrolled

Exclusion Criteria:

1. Age<18 years.
2. Individuals with hypertension, diabetes, obesity, metabolic syndrome or pregnancy.
3. Individuals who received gastrointestinal operation, antibiotics or probiotic products within one month.

Inclusion Criteria:

1. Confirmed CKD patients.
2. Age≥18 years.

Exclusion criteria：

1. Age<18 years.
2. Patients with active gastrointestinal diseases, liver cirrhosis, cancer, active infection or cardiovascular event in the past 3 months, pregnancy or received renal replacement therapy.