Project Description:

Hyperphosphatemia is a late complication in chronic kidney disease (CKD) derived from the loss of homeostasis in mineral and bone metabolism, and a key biochemical alteration driving the pathogenesis of CKD-mineral and bone disorder (CKD-MBD). Current treatments for hyperphosphatemia have focused on limiting dietary phosphorus intake and absorption through a phosphorus-limited diet and medications that limit intestinal phosphorus absorption. However, despite these approaches, serum phosphorus levels remain elevated in patients undergoing hemodialysis in the United States, highlighting the urgent need for innovative therapies.

We recently showed that inulin, a prebiotic fermentable dietary fiber, slowed the progression of CKD-MBD in a rat model mimicking CKD stages 4 and 5. Specifically, inulin lowered circulating phosphorus and parathyroid hormone, improved cortical bone, and mitigated cardiovascular calcification. Building on this, our preliminary findings revealed that psyllium - a viscous fiber used for the treatment of constipation-similarly improved hyperphosphatemia and other CKD-MBD outcomes in the same rat model. Together, these results suggest that dietary fiber may represent a low-cost, accessible therapy for CKD-MBD management.

The current study aims to translate these promising preclinical findings into a proof-of-concept controlled feeding study in individuals with CKD stages 3b-4. The study will evaluate the effect of inulin and psyllium on mineral balance and homeostasis. The pilot data will establish feasibility, determine effect sizes for key outcomes, and inform sample size calculations for future studies.

The student will be able to participate in the preparation and deployment of the controlled diets and active data and specimen collection, including blood, urine, and fecal samples. Furthermore, the student will have the opportunity to quantify microbial metabolites and biomarkers in blood, urine, and feces of individuals with CKD.

Requirements:

Undergraduate in health-related fields, including Biomedicine, Biology, and Nutrition.