Kidney StoneNCT06330246
O. Formigenes Colonization in Calcium Oxalate Kidney Stone Disease
A study testing Low oxalate fixed diets pre-colonization, Moderately high oxalate fixed diets pre-colonization and Colonization with Oxalobacter formigenes in people with Kidney Stone and Kidney Calculi, run by University of Alabama at Birmingham at 2 sites in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 80 years
- Conditions the study is for
- Kidney Stone, Kidney Calculi, Urolithiasis
- What is being tested?
- Low oxalate fixed diets pre-colonization, Moderately high oxalate fixed diets pre-colonization and Colonization with Oxalobacter formigenes
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 2 sitesUnited States
- Study dates
- 17 Apr 2024to 31 Dec 2031
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- age 19-80 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
Who cannot join
- 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
Show all 10Show fewer
- Utilization of immunosuppressive medication
- Uncontrolled Hypertension or diabetes
- Diabetes type 1
- Current Colonization with Oxalobacter formigenes
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United States2 sites, 2 recruiting
- Recruiting
University of Alabama at Birmingham
Birmingham, Alabama, 35294
Sonia Fargue, PhD, 2059756932, sfargue@uab.edu
Research Coordinator, 2059345712, kidneystone@uabmc.edu
- Recruiting
UTSW
Dallas, Texas, 75390
Naim Maalouf, MD, Naim.Maalouf@UTSouthwestern.edu
Esperanza Jackson, Esperanza.Jackson@UTSouthwestern.edu
About this study
Official title: Oxalobacter Formigenes Colonization in Calcium Oxalate Kidney Stone Formers
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
Read the detailed description
In this study the investigators propose to measure the excretion of urinary oxalate on a fixed diet with controlled amounts of oxalate, before and after inducing colonization with the gut bacteria Oxalobacter formigenes in individuals with a history of calcium oxalate kidney stones not already colonized with Oxalobacter formigenes.
Screening and Pre-colonization phase. Between the University of Alabama at Birmingham (UAB) and the University of Texas Southwestern Medical Center (UTSW), the study will enroll 40 individuals with a history of idiopathic calcium oxalate kidney (20 males/20 females). Screening will include stool colonization testing, blood complete metabolic profile, 24-hr urine specimens collected at home on self-selected diets and anthropometric measurements.
Participants will ingest a low-oxalate (<60 mg/day) fixed diet for 4 consecutive days and collect two 24-hr urines and a stool sample after 2 days of dietary equilibration, as well as one fasted blood sample on the last morning.
After a wash-out period of at least 1 week, participants will ingest a moderately high-oxalate (250-300 mg/day) fixed diet for 4 consecutive days and collect two 24-hr urines and a stool sample after 2 days of dietary equilibration, as well as one fasted blood sample on the last morning.
Colonization and Post-colonization phase. Participants will be colonized with Oxalobacter formigenes by ingesting a freshly thawed paste of live bacterial preparation of O. formigenes. They will collect a stool sample 1 week later to assess if colonization occured.
After confirmation of successful colonization, participants will ingest a low-oxalate (<60 mg/day) fixed diet for 4 consecutive days and collect two 24-hr urines and a stool sample after 2 days of dietary equilibration, as well as one fasted blood sample on the last morning.
After a wash-out period of at least 1 week, participants will ingest a moderately high-oxalate (250-300 mg/day) fixed diet for 4 consecutive days and collect two 24-hr urines and a stool sample after 2 days of dietary equilibration, as well as one fasted blood sample on the last morning.
Follow-up phase Participants will be followed up every 6 months to assess sustainability of colonization, provide a stool sample and answer a simple questionnaire. A 24-hr urine collection will be requested once a year after colonization, on the same moderately high oxalate diet diet after 2 days of dietary equilibration.
- Conditions
- Kidney Stone, Kidney Calculi, Urolithiasis, Urolithiasis, Calcium Oxalate, Nephrolithiasis, Nephrolithiasis, Calcium Oxalate
- Being tested
- 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
- Medical subject headings
- Kidney Calculi, Urolithiasis, Nephrolithiasis, Calcium Oxalate, Nephrolithiasis, Hyperoxaluria
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Low oxalate fixed diets pre-colonizationDietary supplement
4 days of fixed eucaloric diet with low oxalate (< 60 mg/day), normal calcium (600-1000 mg/day)
Moderately high oxalate fixed diets pre-colonizationDietary supplement
4 days of fixed eucaloric diet with moderately high oxalate (250-300 mg/day), normal calcium (600-1000 mg/day)
Colonization with Oxalobacter formigenesDietary supplement
Ingestion of live Oxalobacter formigenes
Low oxalate fixed diets post-colonizationDietary supplement
4 days of fixed eucaloric diet with low oxalate (< 60 mg/day), normal calcium (600-1000 mg/day)
Moderately high oxalate fixed diets post-colonizationDietary supplement
4 days of fixed eucaloric diet with moderately high oxalate (250-300 mg/day), normal calcium (600-1000 mg/day)
| Study group | Role | What they receive |
|---|---|---|
| colonization with Oxalobacter formigenes | Experimental | Colonization with a live preparation of Oxalobacter formigenes, strain OxCC13. Receives: Dietary Supplement: Low oxalate fixed diets pre-colonization; Dietary Supplement: Moderately high oxalate fixed diets pre-colonization; Dietary Supplement: Colonization with Oxalobacter formigenes; Dietary Supplement: Low oxalate fixed diets post-colonization; Dietary Supplement: Moderately high oxalate fixed diets post-colonization |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in urinary oxalate excretion following colonization with Oxalobacter formigenes
Difference between urinary oxalate excretion on the moderately high oxalate diet pre-colonization and urinary oxalate excretion on the moderately high oxalate diet post-colonization
Measured: 2 months
Secondary outcomes (1)
Sustainability of colonization with Oxalobacter formigenes
duration of colonization after successful induction of colonization sith Oxalobacter formigenes
Measured: 4 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Mar 2024
- Study start17 Apr 2024
- Primary completion31 Dec 2030 (estimated)
- Study completion31 Dec 2031 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Kidney StoneStudies of the same condition, open and under way.
- More trials run by University of Alabama at BirminghamThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- None (open label)
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Alabama at Birmingham
- Sponsor type
- University, hospital or other
- Collaborators
- University of Texas Southwestern Medical Center, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Responsible party
- Principal investigator, Sonia Fargue, University of Alabama at Birmingham
- Investigators
- Sonia Fargue, PhD, Principal investigator, University of Alabama at Birmingham
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06330246
- Sponsor's protocol ID
- IRB300005280-OCK
- Other IDs
- R01DK137784
- Status last verified
- Oct 2026
- First submitted
- 19 Mar 2024
- Last updated
- 13 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 13 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Oxalobacter Formigenes Colonization in Calcium Oxalate Kidney Stone Formers
- ClinicalTrials.gov ID
- NCT06330246
- Acronym / sponsor ID
- IRB300005280-OCK
- Conditions
- Kidney Stone, Kidney Calculi, Urolithiasis, Urolithiasis, Calcium Oxalate, Nephrolithiasis, Nephrolithiasis, Calcium Oxalate
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- University of Alabama at BirminghamUniversity, hospital or other
- Collaborators
- University of Texas Southwestern Medical Center, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Study start
- 17 Apr 2024 (actual)
- Primary completion
- 31 Dec 2030 (estimated)
- Study completion
- 31 Dec 2031 (estimated)
- First posted
- 26 Mar 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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
Detailed description
In this study the investigators propose to measure the excretion of urinary oxalate on a fixed diet with controlled amounts of oxalate, before and after inducing colonization with the gut bacteria Oxalobacter formigenes in individuals with a history of calcium oxalate kidney stones not already colonized with Oxalobacter formigenes.
Screening and Pre-colonization phase. Between the University of Alabama at Birmingham (UAB) and the University of Texas Southwestern Medical Center (UTSW), the study will enroll 40 individuals with a history of idiopathic calcium oxalate kidney (20 males/20 females). Screening will include stool colonization testing, blood complete metabolic profile, 24-hr urine specimens collected at home on self-selected diets and anthropometric measurements.
Participants will ingest a low-oxalate (<60 mg/day) fixed diet for 4 consecutive days and collect two 24-hr urines and a stool sample after 2 days of dietary equilibration, as well as one fasted blood sample on the last morning.
After a wash-out period of at least 1 week, participants will ingest a moderately high-oxalate (250-300 mg/day) fixed diet for 4 consecutive days and collect two 24-hr urines and a stool sample after 2 days of dietary equilibration, as well as one fasted blood sample on the last morning.
Colonization and Post-colonization phase. Participants will be colonized with Oxalobacter formigenes by ingesting a freshly thawed paste of live bacterial preparation of O. formigenes. They will collect a stool sample 1 week later to assess if colonization occured.
After confirmation of successful colonization, participants will ingest a low-oxalate (<60 mg/day) fixed diet for 4 consecutive days and collect two 24-hr urines and a stool sample after 2 days of dietary equilibration, as well as one fasted blood sample on the last morning.
After a wash-out period of at least 1 week, participants will ingest a moderately high-oxalate (250-300 mg/day) fixed diet for 4 consecutive days and collect two 24-hr urines and a stool sample after 2 days of dietary equilibration, as well as one fasted blood sample on the last morning.
Follow-up phase Participants will be followed up every 6 months to assess sustainability of colonization, provide a stool sample and answer a simple questionnaire. A 24-hr urine collection will be requested once a year after colonization, on the same moderately high oxalate diet diet after 2 days of dietary equilibration.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| colonization with Oxalobacter formigenes | Experimental | Dietary Supplement: Low oxalate fixed diets pre-colonization, Dietary Supplement: Moderately high oxalate fixed diets pre-colonization, Dietary Supplement: Colonization with Oxalobacter formigenes, Dietary Supplement: Low oxalate fixed diets post-colonization, Dietary Supplement: Moderately high oxalate fixed diets post-colonizationColonization with a live preparation of Oxalobacter formigenes, strain OxCC13. |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- age 19-80 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
Key exclusion criteria (10 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Low oxalate fixed diets pre-colonization4 days of fixed eucaloric diet with low oxalate (< 60 mg/day), normal calcium (600-1000 mg/day) | Dietary supplement | colonization with Oxalobacter formigenes |
| Moderately high oxalate fixed diets pre-colonization4 days of fixed eucaloric diet with moderately high oxalate (250-300 mg/day), normal calcium (600-1000 mg/day) | Dietary supplement | colonization with Oxalobacter formigenes |
| Colonization with Oxalobacter formigenesIngestion of live Oxalobacter formigenes | Dietary supplement | colonization with Oxalobacter formigenes |
| Low oxalate fixed diets post-colonization4 days of fixed eucaloric diet with low oxalate (< 60 mg/day), normal calcium (600-1000 mg/day) | Dietary supplement | colonization with Oxalobacter formigenes |
| Moderately high oxalate fixed diets post-colonization4 days of fixed eucaloric diet with moderately high oxalate (250-300 mg/day), normal calcium (600-1000 mg/day) | Dietary supplement | colonization with Oxalobacter formigenes |
Primary outcome
Change in urinary oxalate excretion following colonization with Oxalobacter formigenes
Time frame: 2 months
Difference between urinary oxalate excretion on the moderately high oxalate diet pre-colonization and urinary oxalate excretion on the moderately high oxalate diet post-colonization
1 secondary outcome
Sustainability of colonization with Oxalobacter formigenes
Time frame: 4 years
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Oct 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Sonia Fargue, PhD principal investigator
University of Alabama at Birmingham
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Low oxalate fixed diets pre-colonization, Moderately high oxalate fixed diets pre-colonization and Colonization with Oxalobacter formigenes in people with Kidney Stone and Kidney Calculi, run by University of Alabama at Birmingham at 2 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 13 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Sonia Fargue, PhD (2059756932, sfargue@uab.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in urinary oxalate excretion following colonization with Oxalobacter formigenes (time frame: 2 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Oct 2026.