Dietary Oxalate and Innate Immunity in Kidney Stone Disease

Dietary Oxalate and Innate Immunity in Kidney Stone Disease

This study will test whether oxalate stimulates urinary crystals and impacts the immune system in healthy subjects using two controlled diets (low and high oxalate).

Oxalate is a small molecule found in plants and plant-derived food. It has been shown that meals containing high amounts of oxalate can increase urinary oxalate excretion, which is a risk factor for calcium oxalate kidney stones (CaOx KS). Small increases in oxalate can stimulate urinary crystals to form which can elicit an immune response. This study consists of having healthy subjects consume both low and oxalate enriched diets to evaluate the effect of oxalate on urinary crystals and immune responses. Participants will receive a low or high oxalate diet for 4 days prior to having a wash out period for 6 days. Participants will then crossover to the opposite oxalate diet for four more days.

Inclusion Criteria:

• Healthy subjects (men and women) between the ages of 18 and 60 years of age
• No calcium oxalate kidney stones or other medical conditions
• Normal comprehensive metabolic panel (CMP)
• Non tobacco users
• Not pregnant
• BMI between 20-30 kg/m2
• Willing to abstain from vigorous exercise and vitamins/supplements during the study
• Willing to consume only provided diets, accurately collect 24-hour urine samples, and have blood drawn

Exclusion Criteria:

• Inability to sign and read the informed consent
• Any medical, psychiatric, or social conditions that would prohibit participants from abiding by the study requirements
• Physician refusal
• Pregnant women
• Active medical problems
• History of kidney stones or any medical condition that could influence absorption or excretion of oxalate
• Tobacco users
• Taking medications or dietary supplements
• BMI >30 or <20