NCT03752684

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.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
26

participants targeted

Target at below P25 for not_applicable

Timeline
Completed

Started Apr 2018

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

April 2, 2018

Completed
7 months until next milestone

First Submitted

Initial submission to the registry

October 22, 2018

Completed
1 month until next milestone

First Posted

Study publicly available on registry

November 26, 2018

Completed
4.4 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

April 27, 2023

Completed
2.1 years until next milestone

Study Completion

Last participant's last visit for all outcomes

May 22, 2025

Completed
19 days until next milestone

Results Posted

Study results publicly available

June 10, 2025

Completed
Last Updated

January 30, 2026

Status Verified

January 1, 2026

Enrollment Period

5.1 years

First QC Date

October 22, 2018

Results QC Date

May 22, 2025

Last Update Submit

January 13, 2026

Conditions

Calcium Oxalate Urolithiasis

Keywords

Oxalobacter formigenesoxalatekidney stones

Outcome Measures

Primary Outcomes (1)

  • Percent Decrease in Urinary Oxalate Excretion After Colonization With O.Formigenes

    Mean 24-hour urine oxalate excretion after colonization with O.formigenes was compared with mean 24-hour urine oxalate before colonization

    4 days

Secondary Outcomes (1)

  • Percentage Decrease in Stool Oxalate Content After Colonization With O.Formigenes

    4 days

Study Arms (1)

Colonization with Oxalobacter formigenes

EXPERIMENTAL

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-colonizedDietary Supplement: Oxalobacter formigenesDietary Supplement: Moderately high oxalate/low calcium diet colonized

Interventions

Moderately high oxalate/low calcium diet colonizedDIETARY_SUPPLEMENT

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

Colonization with Oxalobacter formigenes
Moderately high oxalate/low calcium diet non-colonizedDIETARY_SUPPLEMENT

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

Colonization with Oxalobacter formigenes
Oxalobacter formigenesDIETARY_SUPPLEMENT

Subjects will ingest live preparation of O. formigenes

Colonization with Oxalobacter formigenes

Eligibility Criteria

Age19 Years - 65 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

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

You may not qualify if:

  • 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

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University of Alabama at Birmingham

Birmingham, Alabama, 35294, United States

Location

MeSH Terms

Conditions

Nephrolithiasis, Calcium OxalateKidney Calculi

Condition Hierarchy (Ancestors)

NephrolithiasisKidney DiseasesUrologic DiseasesFemale Urogenital DiseasesFemale Urogenital Diseases and Pregnancy ComplicationsUrogenital DiseasesUrolithiasisUrinary CalculiMale Urogenital DiseasesCalculiPathological Conditions, AnatomicalPathological Conditions, Signs and Symptoms

Results Point of Contact

Title
John Knight
Organization
University of Alabama at Birmingham
johnknight@uabmc.edu
205-996-2295

Study Officials

  • John Knight, PhD

    University of Alabama at Birmingham

    PRINCIPAL INVESTIGATOR

Publication Agreements

PI is Sponsor Employee
No
Restrictive Agreement
No

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NA
Masking
NONE
Purpose
BASIC SCIENCE
Intervention Model
SEQUENTIAL
Model Details: Evaluate urinary oxalate excretion before and after colonization with the oxalate degrading bacterium Oxalobacter formigenes
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Associate Professor

Study Record Dates

First Submitted

October 22, 2018

First Posted

November 26, 2018

Study Start

April 2, 2018

Primary Completion

April 27, 2023

Study Completion

May 22, 2025

Last Updated

January 30, 2026

Results First Posted

June 10, 2025

Record last verified: 2026-01

Data Sharing

IPD Sharing
Will not share

Locations

US(1)