Effect of Pea Hull Fiber on Uremic Metabolites and Gut Microbiota Composition in Individuals Undergoing Hemodialysis

• Published in: Current developments in nutrition 2021-06, Vol.5 (Supplement_2), p.1155-1155
• Main Authors: Fatani, Asmaa, Suh, JoonHyuk, Auger, Jeremie, Wang, Yu, Dahl, Wendy
• Format: Article
• Language: English
• Subjects: Nutritional Microbiology/Microbiome
• ISSN: 2475-2991; 2475-2991
• DOI: 10.1093/cdn/nzab054_010

The objective was to determine the effects of pea hull fiber intake on serum uremic molecules and microbiota composition of individuals undergoing hemodialysis. A randomized, double-blind, placebo-control, crossover study was conducted with individuals undergoing hemodialysis. Following a 1-week baseline, participants consumed muffins with added pea hull fiber (15 g/d) and control muffins daily for 4 weeks in random order, separated by a 4-week washout. Blood and stool samples were collected during each period. Serum p-cresol sulfate (PCS), indoxyl sulfate (IS) and trimethylamine N-oxide (TMAO) were analyzed by LC–MS/MS and fecal microbiome profile by 16S rRNA gene amplicon sequencing. qPCR for taxa of interest (Akkermansia muciniphila, Faecalibacterium prausnitzii, Bifidobacterium, and Roseburia) was performed. QIIME 2 sample-classifier was used to discover a unique microbiota profile due to the consumption of pea hull fiber. Of the 18 participants randomized (50 ± 4 y; eGFR 6.6 ± 0.7 ml/min/1.73m2), 13 completed the study. No significant changes from baseline were observed in serum PCS (3256 ± 505 μmol/L), IS (166 ± 23 μmol/L) or TMAO (96 ± 12 μmol/L), or for the relative quantification of A. muciniphila, F. prausnitzii, Bifidobacterium, and Roseburia, taxa thought to be health enhancing. Taxa that most distinguished the microbiota composition during the pea hull fiber intervention from usual diet periods were enriched Gemmiger, Collinsella and depleted Lactobacillus, Ruminococcus, Coprococcus and Mogibacteriaceae. Given that abundance of Collinsella has been inversely associated with dietary fiber, this finding was unexpected. In dialysis patients, added pea hull fiber did not reduce the serum levels of targeted uremic molecules but did alter fecal microbiota composition. Future research in this patient population should explore the efficacy of alternate fiber sources or plant-based dietary patterns for reducing serum levels of uremic toxins. Saskatchewan Pulse Growers.