Oxalobacter Formigenes Colonization and Urinary Oxalate Excretion

NCT ID: NCT03752684

Last Updated: 2025-06-10

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 26 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2018-04-02
• Study Completion Date: 2025-05-22

Brief Summary

The purpose of this research study is to assess the efficacy of ingesting a small amount of the harmless bacterium Oxalobacter formigenes in establishing residence in the guts of healthy participants and to determine whether this influences the oxalate passed in urine.

Detailed Description

Adults that are not colonized with O. formigenes, have no history of stone disease, and are in good health as judged by their medical history and a complete metabolic profile of their serum, will be recruited from within the greater Birmingham area.

Participants not colonized with O. formigenes will consume a controlled diet containing moderately high levels of oxalate (210-240 mg per day), and low levels of calcium (500 - 700 mg per day) and collect 24-hour urines to measure oxalate excretion. Following completion of urine collections, participants will ingest live O.formigenes and one week later stool will be provided to test for colonization with O.formigenes. Participants that are successfully colonized with O.formigenes will then repeat 24 hour urine collections on the same high oxalate, low calcium diet. Controlled diets will be prepared in the Metabolic Kitchen of the UAB Clinical Research Unit (CRU). Sustainability of colonization will be determined over time. Loss of colonization will be confirmed by having the subject consume an oxalate-rich meal with subsequent testing for O. formigenes.

Conditions

Calcium Oxalate Urolithiasis

Study Design

• Allocation Method: NA
• Intervention Model: SEQUENTIAL
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Colonization with Oxalobacter formigenes

Subjects not colonized with Oxalobacter formigenes will be equilibrated to a moderately high oxalate/ low calcium oxalate controlled diet and collect 24-hour urines to measure oxalate excretion Subjects will then be colonized with Oxalobacter formigenes(Intervention). Following colonization with Oxalobacter formigenes, urinary oxalate will be measured to determine the impact of colonization on the same controlled diet

Group Type: EXPERIMENTAL

Moderately high oxalate/low calcium diet non-colonized

Intervention Type: DIETARY_SUPPLEMENT

Subjects will be instructed to ingest a controlled diet moderately high in oxalate before colonization

Oxalobacter formigenes

Intervention Type: DIETARY_SUPPLEMENT

Subjects will ingest live preparation of O. formigenes

Moderately high oxalate/low calcium diet colonized

Intervention Type: DIETARY_SUPPLEMENT

Subjects will be instructed to ingest a controlled diet moderately high in oxalate after colonization

Interventions

Moderately high oxalate/low calcium diet non-colonized

Subjects will be instructed to ingest a controlled diet moderately high in oxalate before colonization

Intervention Type: DIETARY_SUPPLEMENT

Oxalobacter formigenes

Subjects will ingest live preparation of O. formigenes

Intervention Type: DIETARY_SUPPLEMENT

Moderately high oxalate/low calcium diet colonized

Subjects will be instructed to ingest a controlled diet moderately high in oxalate after colonization

Intervention Type: DIETARY_SUPPLEMENT

Eligibility Criteria

Inclusion Criteria

• Good health as judged from a medical history and reported medications
• Not colonized with O. formigenes

Exclusion Criteria

• History of any hepatic, renal, bowel or endocrine disease or any other condition that may influence the absorption, transport or urinary excretion of ions, which will compromise the interpretation of results
• colonized with O. formigenes
• abnormal urine chemistries or blood metabolic profiles

• Minimum Eligible Age: 19 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

NIH

Sponsor Role: collaborator

University of Alabama at Birmingham

OTHER

Sponsor Role: lead

Responsible Party

John Knight

Associate Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

John Knight, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Alabama at Birmingham

Locations

University of Alabama at Birmingham

Birmingham, Alabama, United States

Countries

United States

Provided Documents

Document Type: Study Protocol and Statistical Analysis Plan

View Document

Document Type: Informed Consent Form

View Document

Other Identifiers

R01DK087967

Identifier Type: NIH

Identifier Source: secondary_id

View Link

IRB-131212001

Identifier Type: -

Identifier Source: org_study_id