Recruiting

Formigenes

Sponsor:

University of Alabama at Birmingham

Code:

NCT06330246

Conditions

Kidney Stone

Kidney Calculi

Urolithiasis

Urolithiasis, Calcium Oxalate

Nephrolithiasis

Eligibility Criteria

Sex: All

Age: 18 - 70

Healthy Volunteers: Not accepted

Interventions

Low oxalate fixed diets pre-colonization

Moderately high oxalate fixed diets pre-colonization

Colonization with Oxalobacter formigenes

Low oxalate fixed diets post-colonization

Moderately high oxalate fixed diets post-colonization

Study Details

Brief summary:

The goal of this trial is to test if colonization with the gut bacteria Oxalobacter formigenes leads to a reduction in urinary oxalate excretion in patients with calcium oxalate kidney stone disease.

The study will recruit adult participants with a history of calcium oxalate kidney stones who are not colonized with Oxalobacter formigenes.

Participants will

  • ingest fixed diets containing low and moderately high amounts of oxalate for 4 days at a time
  • collect urine, blood and stool samples during the fixed diets
  • ingest a preparation of live Oxalobacter formigenes to induce colonization with Oxalobacter formigenes

Conditions

Kidney Stone

Kidney Calculi

Urolithiasis

Urolithiasis, Calcium Oxalate

Nephrolithiasis

Study ID

NCT06330246

Start date

Apr 17, 2024

Status verified date

Aug, 2026

Completion date

Dec 31, 2031

Anticipated

Primary completion date

Dec 31, 2030

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70

Healthy Volunteers: Not accepted

Inclusion Criteria

  • age 19-70 yrs
  • Body Mass Index > 18.5 kg/m2
  • First time or recurrent Calcium Oxalate stone former. Composition of most recent stone ≥ 50% calcium oxalate if available
  • Not colonized with Oxalobacter formigenes
  • Normal fasting serum electrolytes on comprehensive metabolic profile
  • Willing to ingest fixed diets
  • Willing to stop supplements (vitamins including vitamin C, calcium (citrate or carbonate) and other minerals, herbal supplements, nutritional aids, probiotics) for 2 weeks before start and during fixed diet phases.
  • If on medications for stone prevention (e.g. thiazides, citrate, allopurinol), stable dose regimen for at least 2 weeks prior to and during study

Exclusion Criteria

  • Chronic Kidney Disease stage 4-5
  • Primary hyperoxaluria
  • Liver, endocrine or renal diseases (other than idiopathic Calcium Oxalate kidney stones) or any other condition that may influence the absorption, transport or urinary excretion of ions, which will compromise the interpretation of results, including: Cystic fibrosis, Cystinuria, Uric acid stone former, Nephrotic syndrome, Sarcoidosis, Renal tubular acidosis, Primary hyperparathyroidism, Neurogenic bladder, Urinary diversion
  • Pregnancy or breast-feeding
  • Incompatible dietary requirements with the study, food allergies or intolerance to any of the foods in study menus
  • Active malignancy or treatment for malignancy within 12 months prior to screening
  • Utilization of immunosuppressive medication
  • Uncontrolled Hypertension or diabetes
  • Diabetes type 1
  • Current Colonization with Oxalobacter formigenes

Study Design

Enrollment

40 participants

Anticipated

Intervention Model

Sequential

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: colonization with Oxalobacter formigenes

Colonization with a live preparation of Oxalobacter formigenes, strain OxCC13.

Interventions

Low oxalate fixed diets pre-colonization

4 days of fixed eucaloric diet with low oxalate (< 60 mg/day), normal calcium (600-1000 mg/day)

Moderately high oxalate fixed diets pre-colonization

4 days of fixed eucaloric diet with moderately high oxalate (250-300 mg/day), normal calcium (600-1000 mg/day)

Colonization with Oxalobacter formigenes

Ingestion of live Oxalobacter formigenes

Low oxalate fixed diets post-colonization

4 days of fixed eucaloric diet with low oxalate (< 60 mg/day), normal calcium (600-1000 mg/day)

Moderately high oxalate fixed diets post-colonization

4 days of fixed eucaloric diet with moderately high oxalate (250-300 mg/day), normal calcium (600-1000 mg/day)

Primary outcome measure

  • Change in urinary oxalate excretion following colonization with Oxalobacter formigenes [ Time Frame: 2 months ]

Central Contacts and Locations

Central contacts

Sonia Fargue, PhD

2059756932sfargue@uab.edu

Demond Wiley

2059345712kidneystone@uabmc.edu

Locations

University of Alabama at Birmingham

Recruiting

Birmingham, Alabama, United States, 35294

Contacts

Sonia Fargue, PhD

2059756932sfargue@uab.edu

Research Coordinator

2059345712kidneystone@uabmc.edu

Principal Investigator:

Sonia Fargue, PhD

UTSW

Recruiting

Dallas, Texas, United States, 75390

Contacts

Naim Maalouf, MD

Naim.Maalouf@UTSouthwestern.edu

Esperanza Jackson

Esperanza.Jackson@UTSouthwestern.edu

Principal Investigator:

Naim Maalouf, MD

More Information

Sponsor

University of Alabama at Birmingham

Last update posted

Aug 27, 2026

Last verified

Aug, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by University of Alabama at Birmingham on 2026-08-27.