Seres’ pill is an alternative to fecal microbiota transplant (FMT), a treatment for C.difficile that is both well-established and difficult to standardize. Everyone is intimately familiar with the material necessary for FMT, but its microbial components vary with the individual donor, diet and time. That presents some inconsistency and risk that has delayed FDA approval for the procedure.
Moving toward an “off the shelf” product, Seres takes stool from prescreened donors and treats the material with ethanol, killing some microbes and leaving behind bacterial spores that can compete for intestinal real estate with C. difficile. A previous study of Seres’ pill was unsuccessful, inspiring the headline “Sham poo washes out.” More information about the newer study and the company’s plans are in this Science article.
C. difficile colonization sometimes occurs after antibiotics deplete healthier forms of intestinal bacteria. Kraft and colleagues at Emory have been investigating whether FMT can prevent colonization by antibiotic-resistant bacteria in kidney transplant patients, who have (deliberately) dampened immune systems and need to take antibiotics.
In February, the Infectious Diseases Society of America issued new guidelines for fighting Clostridium difficile, the hardy bacterium that can cause life-threatening diarrhea and whose dominance is sometimes a consequence of antibiotic treatment. The guidelines recommend for the first time that FMT (fecal microbiota transplant) be considered for individuals who have repeatedly failed standard antibiotics.
In a nice coincidence, Emory FMT specialists Colleen Kraft and Tanvi Dhere recently published a look at their clinical outcomes with C diff going back to 2012, in Clinical Infectious Diseases. They report 95 percent of patients (122/128) indicated they would undergo FMT again and 70 percent of the 122 said they would prefer FMT to antibiotics as initial treatment if they were to have a recurrence. Read more
How should doctors measure how messed up someoneâ€™s intestinal microbiome is?
This is the topic of a recent paper in American Journal of Infection Controlfrom Colleen Kraft and colleagues from Emory and the Centers for Disease Control and Prevention. The corresponding author is epidemiologist Alison Laufer Halpin at the CDC.
What the authors are moving towards is similar to Shannonâ€™s index, which ecologists use to measure diversity of species. Another way to think about it is like the Gini coefficient, a measure of economic inequality in a country. If there are many kinds of bacteria living in someoneâ€™s body, the disruption index should be low. If there is just one dominant type of bacteria, the disruption index should be high.
In the paper, the authors examined samples from eight patients in a long-term acute care hospital (Wesley Woods) who had recently developed diarrhea. Using DNA sequencing, they determined what types of bacteria were present in patients’ stool. The patientsâ€™ samples were compared with those from two fecal microbial transplant donors. Read more
The capsule study, published Monday in Journal of Infectious Diseases, represents an important step in moving away from fecal microbiota transplant as a treatment for C. difficile, says Colleen Kraft, MD, assistant professor of pathology and laboratory medicine and medicine (infectious diseases) at Emory University School of Medicine.
While this study involving 30 patients did not include a control group, the reported effectiveness of 96.7 percent compares favorably to published results on antibiotic treatment of C. difficile infection or fecal microbial transplant. Read more