Oxalobacter formigenes: a potential tool for the treatment of primary hyperoxaluria type 1

Kidney Int. 2006 Oct;70(7):1305-11. doi: 10.1038/sj.ki.5001707. Epub 2006 Jul 19.


Primary hyperoxaluria is characterized by severe urolithiasis, nephrocalcinosis, and early renal failure. As treatment options are scarce, we aimed for a new therapeutic tool using colonic degradation of endogenous oxalate by Oxalobactor formigenes. Oxalobacter was orally administered for 4 weeks as frozen paste (IxOC-2) or as enteric-coated capsules (IxOC-3). Nine patients (five with normal renal function, one after liver-kidney transplantation, and three with renal failure) completed the IxOC-2 study. Seven patients (six with normal renal function and one after liver-kidney transplantation) completed the IxOC-3 study. Urinary oxalate or plasma oxalate in renal failure was determined at baseline, weekly during treatment and for a 2-week follow-up. The patients who showed >20% reduction both at the end of weeks 3 and 4 were considered as responders. Under IxOC-2, three out of five patients with normal renal function showed a 22-48% reduction of urinary oxalate. In addition, two renal failure patients experienced a significant reduction in plasma oxalate and amelioration of clinical symptoms. Under IxOC-3 treatment, four out of six patients with normal renal function responded with a reduction of urinary oxalate ranging from 38.5 to 92%. Although all subjects under IxOC-2 and 4 patients under IxOC-3 showed detectable levels of O. formigenes in stool during treatment, fecal recovery dropped directly at follow up, indicating only transient gastrointestinal-tract colonization. The preliminary data indicate that O. formigenes is safe, leads to a significant reduction of either urinary or plasma oxalate, and is a potential new treatment option for primary hyperoxaluria.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Adolescent
  • Adult
  • Capsules
  • Child
  • Child, Preschool
  • Chromatography, Gas
  • Creatinine / urine
  • Feces / microbiology
  • Female
  • Flame Ionization
  • Follow-Up Studies
  • Humans
  • Hyperoxaluria, Primary / blood
  • Hyperoxaluria, Primary / classification
  • Hyperoxaluria, Primary / complications
  • Hyperoxaluria, Primary / therapy*
  • Hyperoxaluria, Primary / urine
  • Kidney / physiology
  • Kidney Diseases / complications
  • Kidney Diseases / diagnostic imaging
  • Kidney Failure, Chronic / complications
  • Kidney Function Tests
  • Kidney Transplantation
  • Male
  • Middle Aged
  • Oxalates / blood
  • Oxalates / urine
  • Oxalobacter formigenes* / isolation & purification
  • Time Factors
  • Treatment Outcome
  • Ultrasonography


  • Capsules
  • Oxalates
  • Creatinine