['To determine the effects of supplemental fiber on plasma p-cresol, stool frequency, and quality of life (QoL) in chronic kidney disease (CKD) patients.', 'In a 12-week single-blind study, participants were provided with control muffins and supplements (5.5\xa0g sucrose/day) for 2\xa0weeks, muffins containing 10\xa0g/day pea hull fiber and control supplements for 4\xa0weeks, and muffins with 10\xa0g/day pea hull fiber and 15\xa0g/day inulin as a supplement for 6\xa0weeks.', 'Individuals with CKD (n\xa0=\xa013; 6 males, 7 females; aged 65\xa0±\xa03\xa0years; estimated glomerular filtration rate <50\xa0mL/minute/1.73(2)) completed the study.', 'Plasma p-cresol was determined by gas chromatography-mass spectrometry, stool frequency by 5-day journals, and QoL by the KDQOL-36™.', 'Plasma p-cresol decreased from 7.25\xa0±\xa01.74\xa0mg/L during week 1 to 5.82\xa0±\xa01.72\xa0mg/L during week 12 (P\xa0<\xa0.05), and in participants with high compliance (>70% inulin intake), from 6.71\xa0±\xa01.98\xa0mg/L to 4.22\xa0±\xa01.16\xa0mg/L (P\xa0<\xa0.05). Total fiber intake increased from 16.6\xa0±\xa01.7\xa0g/day during control to 26.5\xa0±\xa02.4\xa0g/day (P\xa0<\xa0.0001) with the added pea hull and to 34.5\xa0±\xa02.2\xa0g/day with pea hull and inulin (P\xa0<\xa0.0001). Stool frequency increased from 1.4\xa0±\xa00.2 stools/day during control to 1.9\xa0±\xa00.3 stools/day during both fiber periods (P\xa0<\xa0.05). No change in overall QoL was observed.'] Does fiber supplementation lower plasma p-cresol in chronic kidney disease patients?