Potential Role of Gastrointestinal Microflora in Increased Acid Production in Patients with Uric Acid Nephrolithiasis

Study ID
STU 092012-029

Cancer Related
No

Healthy Volunteers
Yes

Study Sites

Contact
Ashlei Johnson-Wilder
214-648-0394
ashlei.johnson@utsouthwestern.edu

Principal Investigator
Khashayar Sakhaee

Summary

aim 1a: To determine endogenous acid production by analyzing urinary constituents, urinary metabolomics, and stool microbiome using a metabolic balance technique in patients with ua nephrolithiasis following combined treatment with oral Metronidazole and Ciprofloxacin.

Study design: a cross-sectional metabolic balance study designed to explore whether endogenous acid production subsides following combined treatment with oral Metronidazole and Ciprofloxacin. our hypothesis is that higher endogenous acid production and subtle Gi alkali loss in ua nephrolithiasis is, in part, due to differences in bacterial microflora metabolism in uric acid stone formers.

aim 1b: To determine endogenous acid production and Gi alkali loss by analyzing dietary, urinary, and fecal constituents using a metabolic balance technique in patients with ua nephrolithiasis and matched lean normal subjects following combined oral Metronidazole and Ciprofloxacin treatment.

Study design: a cross-sectional metabolic balance study designed to explore whether endogenous acid production and subtle Gi alkali loss subsides following combined treatment with oral Metronidazole and Ciprofloxacin. our hypothesis is that higher endogenous acid production and subtle Gi alkali loss in ua nephrolithiasis is, in part, due to the differences in gastrointestinal microflora in uric acid stone formers. We further hypothesize that obesity is associated with a gastrointestinal microflora that resembles the microflora of uric acid stone formers, thus potentially explaining the epidemiologic association between obesity and uric acid nephrolithiasis.

Participant Eligibility

Aim 1a: Inclusion criteria: Adult subjects with idiopathic uric acid nephrolithiasis, age > 21 years of either sex, of any ethnicity. Subjects will be recruited from UT Southwestern Medical Center.

Aim 1b:
Group 1 - Adult subjects with UA nephrolithiasis, age > 21 years of either sex, of any ethnicity. All subjects will be recruited from our previous study databases.
Group 2 - Lean adult subjects (BMI<25), gender-matched and age-matched (within 5 years) to UA stone former subjects from group 1, with no known history of kidney stones. All subjects will be recruited by campus and community-wide advertising.
Group 3 - Obese adult subjects (BMI>30), gender-matched and age-matched (within 5 years) to UA stone former subjects from group 1, with no known history of kidney stones or diabetes. All subjects will be recruited by campus and community-wide advertising.