Adventures in the microbiome (part 1)

There's a really interesting new paper in Clinical Infectious Diseases on a novel treatment for recurrent C. difficile infection. In this retrospective, uncontrolled experience, 25 patients with recurrent C. difficile infection (mean number of relapses = 4, median days of illness = 135) were treated with either metronidazole or oral vancomycin, along with kefir (5 oz three times daily). The antibiotics were given for 2 weeks at a standard dose (i.e., vancomycin 125 mg every 6 hours). In the next 2 week period, it was given at 3 times standard dose once every 72 hours (i.e., 375 mg), followed by 2 weeks of 2 times standard dose every 72 hours, then 2 weeks of standard dose every 72 hours. This strategy is known as staggered and tapered antibiotic withdrawal (STAW). The kefir was continued for 2 months after the antibiotic was discontinued.

I had to learn about kefir as I knew very little about it. It's essentially milk in which the lactose has been fermented by bacteria. It contains 10 strains of bacteria at a concentration of 7-10 billion CFU/cup. Thus, it's a big gun probiotic, and comes in several different flavors and forms (liquid, frozen, yogurt, cheese). You can find it in most grocery stores.

The end result was that 84% of the patients treated with STAW + kefir were diarrhea-free at 9 months. Again, this was an uncontrolled study, but nonetheless quite intriguing. I will certainly try this regimen in patients with recurrent C. difficile as an option for patients who either don't want to have a fecal transplant or would like to try this before resorting to transplant. I also wonder whether we should be serving kefir to hospitalized, nonimmunosuppressed patients as a prophylactic strategy for C. difficile. This weekend, I'll sample some of the products myself.

Tomorrow, I'll tell you about another interesting manipulation of the gut microbiome.