Dietary Oxalate and Innate Immunity in Kidney Stone Disease

NCT ID: NCT04051346

Last Updated: 2025-05-08

Basic Information

• Recruitment Status: ACTIVE_NOT_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 20 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2021-03-05
• Study Completion Date: 2026-05-01

Brief Summary

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).

Detailed Description

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.

Conditions

Kidney Stone

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: SINGLE

Study Groups

Low Oxalate Diet Followed by High Oxalate Diet

Subjects will consume a low oxalate diet for four days, with blood and 24-hour urine collections occurring at baseline and post diet. A ten day wash out period will follow, during which the subject will consume a self-selected diet. Subjects will then consume the high oxalate diet for the final four days, with blood and 24-hour urine collections once again occurring at baseline and post diet.

Group Type: EXPERIMENTAL

Low Oxalate Diet

Intervention Type: DIETARY_SUPPLEMENT

Participants will consume a diet that is controlled in its daily contents of oxalate and calcium, and in its content of carbohydrate, fat, and protein. Participants will be asked not to take any dietary supplements, to exercise strenuously, or to consume food or drink that is not provided to them

High Oxalate Diet

Intervention Type: DIETARY_SUPPLEMENT

Participants will consume a diet that is controlled in its daily contents of oxalate and calcium, and in its content of carbohydrate, fat, and protein. Participants will be asked not to take any dietary supplements, to exercise strenuously, or to consume food or drink that is not provided to them.

High Oxalate Diet Followed by Low Oxalate Diet

Subjects will consume a high oxalate diet for four days, with blood and 24-hour urine collections occurring at baseline and post diet. A ten day wash out period will follow, during which the subject will consume a self-selected diet. Subjects will then consume the low oxalate diet for the final four days, with blood and 24-hour urine collections once again occurring at baseline and post diet.

Group Type: EXPERIMENTAL

Low Oxalate Diet

Intervention Type: DIETARY_SUPPLEMENT

Participants will consume a diet that is controlled in its daily contents of oxalate and calcium, and in its content of carbohydrate, fat, and protein. Participants will be asked not to take any dietary supplements, to exercise strenuously, or to consume food or drink that is not provided to them

High Oxalate Diet

Intervention Type: DIETARY_SUPPLEMENT

Participants will consume a diet that is controlled in its daily contents of oxalate and calcium, and in its content of carbohydrate, fat, and protein. Participants will be asked not to take any dietary supplements, to exercise strenuously, or to consume food or drink that is not provided to them.

Interventions

Low Oxalate Diet

Participants will consume a diet that is controlled in its daily contents of oxalate and calcium, and in its content of carbohydrate, fat, and protein. Participants will be asked not to take any dietary supplements, to exercise strenuously, or to consume food or drink that is not provided to them

Intervention Type: DIETARY_SUPPLEMENT

High Oxalate Diet

Participants will consume a diet that is controlled in its daily contents of oxalate and calcium, and in its content of carbohydrate, fat, and protein. Participants will be asked not to take any dietary supplements, to exercise strenuously, or to consume food or drink that is not provided to them.

Intervention Type: DIETARY_SUPPLEMENT

Eligibility Criteria

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

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 60 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of Alabama at Birmingham

OTHER

Sponsor Role: lead

Responsible Party

Tanecia Mitchell, PhD

Principal Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Tanecia Mitchell, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Alabama at Birmingham

Locations

University of Alabama at Birmingham

Birmingham, Alabama, United States

Countries

United States

Other Identifiers

IRB-300003865

Identifier Type: -

Identifier Source: org_study_id