Calcium Oxalate Urolithiasis
Conditions
Keywords
Oxalobacter formigenes, oxalate, kidney stones
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.
Interventions
DIETARY_SUPPLEMENTModerately high oxalate/low calcium diet non-colonized
Subjects will be instructed to ingest a controlled diet moderately high in oxalate before colonization
DIETARY_SUPPLEMENTOxalobacter formigenes
Subjects will ingest live preparation of O. formigenes
DIETARY_SUPPLEMENTModerately high oxalate/low calcium diet colonized
Subjects will be instructed to ingest a controlled diet moderately high in oxalate after colonization
Sponsors
University of Alabama at Birmingham
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Study design
Allocation
NA
Intervention model
SEQUENTIAL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
Evaluate urinary oxalate excretion before and after colonization with the oxalate degrading bacterium Oxalobacter formigenes
Eligibility
Sex/Gender
ALL
Age
19 Years to 65 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Percent Decrease in Urinary Oxalate Excretion After Colonization With O.Formigenes | 4 days | Mean 24-hour urine oxalate excretion after colonization with O.formigenes was compared with mean 24-hour urine oxalate before colonization |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Percentage Decrease in Stool Oxalate Content After Colonization With O.Formigenes | 4 days | Mean stool oxalate content after colonization with O.formigenes was compared with mean stool oxalate before colonization |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORJohn Knight, PhD
University of Alabama at Birmingham
Participant flow
Recruitment details
Participants were recruited within the Greater Birmingham area
Participants by arm
| Arm | Count |
|---|---|
| Colonization With Oxalobacter Formigenes Moderately high oxalate/low calcium diet non-colonized: Participants not colonized with O.formigenes will collect 24-hour urines on the controlled diet
Oxalobacter formigenes: Participants will ingest live preparation of O. formigenes
Moderately high oxalate/low calcium diet colonized: Participants successfully colonized with O.formigenes will collect 24-hour urines on the same controlled diet | 22 |
| Total | 22 |
Baseline characteristics
| Characteristic | Colonization With Oxalobacter Formigenes |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 22 Participants |
| Body Mass Index | 29 kg per m2 STANDARD_DEVIATION 5 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants |
| Race (NIH/OMB) Black or African American | 8 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 13 Participants |
| Region of Enrollment United States | 22 participants |
| Sex: Female, Male Female | 10 Participants |
| Sex: Female, Male Male | 12 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 22 |
| other Total, other adverse events | 0 / 22 |
| serious Total, serious adverse events | 0 / 22 |
Outcome results
Primary
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
Time frame: 4 days
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Colonization With Oxalobacter Formigenes | Percent Decrease in Urinary Oxalate Excretion After Colonization With O.Formigenes | 14 Percentage decrease in urinary oxalate |
Secondary
Percentage Decrease in Stool Oxalate Content After Colonization With O.Formigenes
Mean stool oxalate content after colonization with O.formigenes was compared with mean stool oxalate before colonization
Time frame: 4 days
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Colonization With Oxalobacter Formigenes | Percentage Decrease in Stool Oxalate Content After Colonization With O.Formigenes | 54 Percentage decrease in stool oxalate |