Fecal Transplants Bring Hope to Patients, Challenge the FDA

Janis C. Kelly


December 15, 2014

In This Article

Standard Treatment Strategies

Faulty Logic Behind Antibiotic Treatment

CDI is defined in the American College of Gastroenterology (ACG) guidelines as "acute onset of diarrhea with documented toxigenic C difficile or its toxin and no other documented cause for diarrhea."[7] Standard treatment guidelines focus on discontinuing the offending antibiotic and treating with other antibiotics.

The rationale behind FMT as treatment is that CDI often develops after conventional antibiotic therapy has disrupted the normal gut microbiome. Dr Brandt said that FMT using feces from a healthy donor is intended to reintroduce normal bacteria into the colon, restore phylogenetic diversity, and make the patient more resistant to colonization by C difficile.

Elaine O. Petrof, MD, associate professor of medicine, Queen's University School of Medicine in Kingston, Ontario, Canada, and Emma Allen-Vercoe, PhD, associate professor of molecular and cellular biology at the University of Guelph, Ontario, Canada, developed a synthetic stool transplant for treating C difficile. They commented, "The treatment of a disease that is largely caused by the effects of antibiotic exposure with yet more antibiotics is counterintuitive, akin to attempting to remove weeds from a lawn by setting fire to the grass. In this light, it is not surprising that the standard therapies for CDI are failing and that the incidence of recurrent CDI is rising. A more insightful approach to the management of the disease would involve the replenishment or replacement of the protective gut microbiota; crowding out the dandelions with healthy new turf."[8]

Current Treatment Recommendations

For an initial case of CDI, the ACG recommends[7] discontinuing the contributing antimicrobial agent and treating mild to moderate cases with metronidazole. For severe CDI or for patients not responding to metronidazole, the ACG recommends vancomycin. Recommended treatment for a first recurrence of CDI is to repeat the regimen used for the initial episode unless the CDI is severe, in which case the patient should be switched to vancomycin. For a second recurrence, the ACG recommends a pulsed vancomycin regimen. For a third recurrence after this, the ACG recommends considering FMT.

The IDSA guidelines, which are currently under revision, are similar but do not include FMT.[6]

According to Dr Brandt, the ACG guidelines are effective in most CDI cases, but recurrence rates are still 15%-35%, and risk increases with each subsequent recurrence. After a second recurrence, the risk for a third recurrence rises to 65%.


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