The overall objective of the study is to examine the changes within the gut microbiome after the supplementation of inulin and its effect on markers of mineral metabolism and bone turnover.

In this randomized controlled cross-over study, twenty HD patients (10 male/10 female, aged 20-80) will be recruited from local dialysis clinics in Champaign-Urbana, IL. After baseline testing, patients will be randomized to the intervention group or placebo group (maltodextrin). Patients will consume inulin (females 10g/day, males 15g/day) or maltodextrin (females 10g/day, males 15g/day) for one month, rest for two weeks (washout period), and continue with the other treatment (either inulin or maltodextrin) for another month. Outcomes will be assessed at the beginning of each period and after a month of supplementation at both periods.

Inclusion Criteria:

• Receive HD therapy 3 days per week and for at least 3 months

Exclusion Criteria:

• Sustained hypercalcemia (>3months).
• Previous major gastrointestinal disease diagnosis (e.g., inflammatory bowel disease and celiac disease).
• Antibiotic treatment < 2 weeks prior the start of the study.