Oxalobacter Formigenes Colonization and Urinary Oxalate Excretion
Study Details
Study Description
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 human subjects and to determine whether this influences the oxalate passed in urine of healthy volunteers.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
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, a complete metabolic profile of their serum, and ranges of ions that influence stone formation in two 24-hour urine collections, will be recruited from within the greater Birmingham area. Recruited subjects will be between the ages of 18 to 65 years and with a BMI >19 and <32.
Subjects not colonized with O. formigenes will consume, firstly, a controlled diet containing 50 mg oxalate and 1000mg calcium (low oxalate/normal calcium diet), followed by a 250 mg oxalate/400mg calcium controlled diet (moderately high oxalate/low calcium diet), with at least a one week washout between each diet, and then repeat the same sequence of diets after colonization with O.formigenes Group 1 strain OxCC13. Controlled diets will be prepared in the Metabolic Kitchen of the UAB Clinical Research Unit (CRU). Each subject will perform a sodium 13C2-oxalate oral load once at the end of each of the two dietary phases to assess dietary oxalate absorption. 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 Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Low Oxalate Diet Subjects not colonized with Oxalobacter formigenes will be equilibrated to a low oxalate diet to determine baseline oxalate values in urine and plasma. Subjects will be colonized with Oxalobacter formigenes (Intervention). Following colonization with Oxalobacter formigenes, urinary and plasma oxalate will be measured to determine the impact of colonization. |
Other: Low Oxalate Diet
Subjects will be instructed to ingest a controlled diet low in oxalate
|
| Experimental: Moderately high oxalate/low calcium diet Subjects not colonized with Oxalobacter formigenes will be equilibrated to a moderately high oxalate/ low calcium oxalate diet to enhance dietary oxalate absorption. Subjects will be colonized with Oxalobacter formigenes(Intervention). Following colonization with Oxalobacter formigenes, urinary and plasma oxalate will be measured to determine the impact of colonization. |
Other: Moderately high oxalate/low calcium diet
Subjects will be instructed to ingest a controlled diet moderately high in oxalate
|
| Experimental: Oxalobacter formigenes Subjects will ingest a liver preparation of O.formigenes |
Other: Oxalobacter formigenes
Subjects will ingest liver preparation of O. formigenes
|
Outcome Measures
Primary Outcome Measures
- Measurement of urinary oxalate by ion chromatography mass spectrometry [1st 24 hour collection]
1st 24 hour urine collection, started 24 hours after initiation of controlled diet
- Measurement of urinary oxalate by ion chromatography mass spectrometry [2nd 24 hour collection]
48 hours post diet
- Measurement of urinary oxalate by ion chromatography mass spectrometry [3rd 24 hour collection]
72 hours post diet
- Measurement of urinary oxalate by ion chromatography mass spectrometry [4th 24 hour urine collection]
96 hours post diet
Secondary Outcome Measures
- Measurement of stool oxalate by ion chromatography mass spectrometry [Stool collected 48-96 hours post diet]
First bowel movement collected during days 2 through 4 of dietary control
- Measurement of stool oxalate by ion chromatography mass spectrometry [Stool collected 48-96 hours post diet]
Second bowel movement collected during days 2 through 4 of dietary control
- Measurement of stool oxalate by ion chromatography mass spectrometry [Stool collected 48-96 hours post diet]
Third bowel movement collected during days 2 through 4 of dietary control
- Measurement of plasma oxalate by ion chromatography coupled with mass spectrometry [Fasted plasma 4 days post diet]
Fasted plasma oxalate after 4 days of controlled diet
Eligibility Criteria
Criteria
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
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abnormal urine chemistries or blood metabolic profiles
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | University of Alabama at Birmingham | Birmingham | Alabama | United States | 35294 |
Sponsors and Collaborators
- University of Alabama at Birmingham
Investigators
- Principal Investigator: John Knight, PhD, University of Alabama at Birmingham
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- IRB-131212001