The purpose of this study is to determine the effects of daily consumption of snacks with and without pea hull fiber on gastrointestinal function, gastrointestinal symptoms, food intake, appetite, changes in fecal and microbial composition and activity. Fifty maintenance hemodialysis hemodialysis and CKD patients in stage 4 or 5 will be recruited to participate in a randomized, blinded, 13-week cross-over study evaluating snack foods containing 15 g/d of pea hull fiber.

Maintenance hemodialysis hemodialysis and CKD patients in stage 4 or 5 (n=50) will be recruited for the study. A randomized, controlled, double-blind, cross-over study will be carried out. Following a 1-week baseline, participants will be assigned to receive snacks with pea hull fiber or control followed by a 4-week wash-out period, and then crossed over to the second intervention. Snacks with added pea hull fiber (15 g/d) and control will be provided to participants in identical packaging. Participants will collect 4 days of stools during the baseline week, week 5, 9, and 13 and analyzed for mineral content. Microbiota composition will be analyzed including microbial diversity, qPCR to quantify changes and 16S rRNA sequencing to identify pea hull fiber effects on specific bacteria. Following baseline, participants will attend a second visit and anthropometric and demographic information will be collected and we will measure blood pressure, the body composition by bioelectrical impedance analysis (BIA), and handgrip strength using a dynamometer.

Throughout the study, participants must complete a daily questionnaire to evaluate the transit time (eg. Bristol Stool Scale), stool frequency, and compliance. Every week, questionnaires to evaluate appetite (eg. SNAQ) and GI wellness (eg. GSRS - Gastrointestinal Symptom Response Scale) will be administered. During each study visit, participants will complete a questionnaire to evaluate the quality of life. In addition, the dietary data (24-hour diet recalls) will be collected by phone during the baseline week and during the last week of each period. During baseline, treatment and each washout, fasting blood will be collected and analyzed for a comprehensive metabolic panel with eGFR, in addition to microbial metabolites (e.g., indoxyl sulfate and p-cresyl sulfate), and inflammatory markers (e.g. CRP, TNFα, IL-6).

Inclusion Criteria:

• 18-85 years of age.
• Kidney disease stage 4 or 5 (including dialysis).
• Willing and able to complete the Consent Form in English.
• Willing to have height, weight, blood pressure, handgrip strength, and body composition measured and provide demographic information (e.g. age, race, sex).
• Willing to consume pea hull fiber snack or control snack for a 56-day period, 28 day for each type of snack.
• Willing to complete a daily, and weekly, and monthly questionnaires regarding appetite, wellness, and transit time, and quality of life throughout the entire 13-week study.
• Willing to provide three 24-hr diet recalls by phone during baseline and last week of each period.
• Willing to provide 16 days of stools and 4 blood samples throughout the study.

Exclusion Criteria:

• Do not meet the above criteria.
• Have known gastrointestinal disease (i.e., inflammatory bowel disease, malignancy, celiac disease), previous colorectal surgery.
• Allergies to ingredients in study foods provided.
• Are pregnant or lactating