Oxalobacter Formigenes Colonization and Urinary Oxalate Excretion

The University of Alabama at Birmingham

Status: Completed

Conditions: Calcium Oxalate Urolithiasis

Treatments: Dietary Supplement: Moderately high oxalate/low calcium diet non-colonized; Dietary Supplement: Moderately high oxalate/low calcium diet colonized; Dietary Supplement: Oxalobacter formigenes

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT03752684

IRB-131212001

R01DK087967 (U.S. NIH Grant/Contract)

Details and patient eligibility

About

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.

Full 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.

Enrollment: 26 patients

Sex: All

Ages: 19 to 65 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Basic Science

Allocation: N/A

Interventional model: Sequential Assignment

Masking: None (Open label)

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26 participants in 1 patient group

Colonization with Oxalobacter formigenes

Experimental group

Description:

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

Treatment:

Dietary Supplement: Oxalobacter formigenes

Dietary Supplement: Moderately high oxalate/low calcium diet colonized

Dietary Supplement: Moderately high oxalate/low calcium diet non-colonized