Oxalobacter Formigenes Colonization and Urinary Oxalate Excretion

January 13, 2026 updated by: John Knight, University of Alabama at Birmingham

Oxalobacter Formigenes Colonization and Oxalate Excretion in Healthy Adults

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

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.

Study Type

Interventional

Enrollment (Actual)

26

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Alabama
      • Birmingham, Alabama, United States, 35294
        • University of Alabama at Birmingham

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

15 years to 61 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: 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
Dietary supplement: Moderately high oxalate/low calcium diet non-colonized
Subjects will be instructed to ingest a controlled diet moderately high in oxalate before colonization
Dietary supplement: Oxalobacter formigenes
Subjects will ingest live preparation of O. formigenes
Dietary supplement: Moderately high oxalate/low calcium diet colonized
Subjects will be instructed to ingest a controlled diet moderately high in oxalate after colonization

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percent Decrease in Urinary Oxalate Excretion After Colonization With O.Formigenes
Time Frame: 4 days
Mean 24-hour urine oxalate excretion after colonization with O.formigenes was compared with mean 24-hour urine oxalate before colonization
4 days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percentage Decrease in Stool Oxalate Content After Colonization With O.Formigenes
Time Frame: 4 days
Mean stool oxalate content after colonization with O.formigenes was compared with mean stool oxalate before colonization
4 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Alabama at Birmingham

Collaborators

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

Investigators

  • Principal Investigator: John Knight, PhD, University of Alabama at Birmingham

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 2, 2018

Primary Completion (Actual)

April 27, 2023

Study Completion (Actual)

May 22, 2025

Study Registration Dates

First Submitted

October 22, 2018

First Submitted That Met QC Criteria

November 21, 2018

First Posted (Actual)

November 26, 2018

Study Record Updates

Last Update Posted (Actual)

January 30, 2026

Last Update Submitted That Met QC Criteria

January 13, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IRB-131212001
  • R01DK087967 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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