Submission
| Title: | The effects of dietary fiber based on fermentability and viscosity on mineral balance and the gut microbiome in a rat model of CKD |
| Presenter: | Annabel Biruete |
| Institution: | Purdue University |
| Authors: | Neal X. Chen- Indiana University School of Medicine Shruthi Srinivasan- Indiana University School of Medicine Kalisha O’Neill- Indiana University School of Medicine David Nelson- Indiana University School of Medicine Kathleen Hill Gallant- University of Minnesota Sharon M. Moe- Indiana University School of Medicine |
Abstract
| Background/Significance/Rationale: | Hyperphosphatemia, or high circulating phosphorus, is a major factor in the pathogenesis of chronic kidney disease-mineral and bone disorder (CKD-MBD). Available therapies vary in their efficacy and focus on phosphorus absorption in the small intestine, ignoring the possible impact of the large intestine. Fiber supplementation based on their physicochemical properties may help us understand the impact of the large intestine on mineral absorption and balance via mechanisms dependent and independent of the gut microbiome. |
| Methods: | 22-week-old male CKD rats were randomly assigned to receive one of four fiber treatments (10% w/w each) based on fermentability and viscosity: 1) Cellulose (-fermentability, -viscosity), 2) inulin (+fermentability, -viscosity), 3) psyllium husk (-fermentability, +viscosity), or 4) pectin (+ fermentability, +viscosity). Treatments lasted 10 weeks, and rats were euthanized at 32 weeks of age (kidney failure). Mineral balance will be assessed by placing rats in metabolic cages for 3 consecutive days during the last week. Cecal/fecal metagenomics and plasma for circulating gut-derived uremic toxins will be assessed at 32 weeks. Tissue collection included all intestinal segments, kidneys, heart, muscle, and bone. |
| Results/Findings: | 70% of the animals have completed the study. Our preliminary data indicates that weight trajectories were similar between treatment groups. The length of the small intestine and the colon were significantly larger in the psyllium-treated rats. Survival at 32 weeks was not statistically significant between groups. |
| Conclusions/Discussion: | In our preliminary analyses, the supplementation of psyllium increased the length of the small and large intestines possibly related to an increased surface area to correct for limiting absorption of nutrients. |
| Translational/Human Health Impact: | The results from this study will help us understand the impact of fiber on mineral balance and develop interventions to be trialed in people with CKD with the goal of improving outcomes in this clinical population. |
