乌鸦传媒

PHILADELPHIA -- Frozen or lyophilized specimens may offer an effective and convenient alternative to fresh stool samples for fecal transplant in patients with recurrent episodes of Clostridium difficile infection, a researcher said here.

Among 13 patients with multiple episodes of C. difficile who were treated with fresh fecal samples, 92% were considered responders at 3 months, as were 93% of 15 patients who received frozen transplants, reported , of the University of Texas in Houston, at the

In addition, 62% of patients who received freeze-dried samples also responded, for an overall 83% response rate.

Those rates included patients who had detectable Clostridium toxin in their stool at the time of fecal transplant. Among the patients who were toxin negative at the time of transplantation, 97% were considered responders, Jiang reported.

The study included 33 patients who had had three or more bouts of C. difficile. Prior to the fecal transplant, they were given a course of oral vancomycin.

Fecal samples were obtained from 10 carefully screened healthy donors and were used within 2 hours if fresh and within 6 months if frozen or lyophilized. Analysis of the donor products determined that all formulations from an individual donor were similar in microbiota composition.

All treatments were given by colonoscopy.

At the time of transplant, two patients receiving the fresh transplant were positive for Clostridium toxin, as were four in the lyophilized group and one in the frozen group.

One patient in each group developed a recurrence of C. difficile infection within a month of the transplant. Two of the patients with recurrences were positive for Clostridium toxin, and only one was toxin negative at the time of the transplant, the researcher noted.

There also was a "dramatic shift" in intestinal microbial flora, she noted. In comparison with samples of donor flora, which were characterized by abundant species of Firmicutes (64%) and Bacteroidetes (21.5%), recipients more often had Proteobacteria (62.3%) and fewer Firmicutes (31.76%).

However, after the transplant, only 6.8% of recipients still had dominant Proteobacteria, while 48.3% had Firmicutes and 24.5% had Bacteroidetes.

There also was an increase in the mucosal-related Verrucomicrobia, which was primarily driven by Akkermansia species. In recipient fecal samples obtained before and after the transplant, this increased from 0.054% to 12.12%.

"The mucosal-associated Akkermansia species may predict improvement in gut barrier function and mutualism between gut microbiota and host," she explained.

"Patients took on the microbial flora characteristics of the donors," commented , an internist in Oklahoma City who was involved in writing the college's guidelines on treating severe C. difficile infection.

"But the results also need to be confirmed in larger numbers of patients. A metabolomic analysis also would be useful, to look at enzymes and activity and see how the bacteria are doing their jobs," Mellow told 乌鸦传媒.

"Being able to use frozen stool, or even to freeze-dry it and put it in a capsule for oral ingestion, would make it much easier to coordinate the donor and recipient," said , director of endoscopy at Brigham and Women's Hospital in Boston, in a "virtual" press conference.

"Future studies are needed to clarify the active therapeutic properties in stools in the treatment of dysbiosis," Jiang concluded.

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