Inclusion Criteria:  Men and women in a ratio of 1:1 Body mass index 18.5 - 34.9 kg/m^2 End-stage kidney disease, which has been treated regularly with hemodialysis for at least 3 months  Exclusion Criteria:  Malignant diseases Recent or current hospitalization Postoperative phase Acute infections Malnutrition Antibiotic treatment within the last 4 weeks Regular intake of probiotics and/or prebiotics Change of body weight of more than 2 kg in the month prior to study entry Known drug or alcohol abuse