From the Journals

Autologous fecal transplant restores microbiota after allo-HSCT



For patients who undergo allogeneic hematopoietic stem cell transplant (allo-HSCT) with intensive antibiotics, a subsequent autologous fecal transplant (auto-FMT) can restore intestinal microbiota, a recent study found.

Dr. Ying Taur of Memorial Sloan Ketting Cancer Center, New York Courtesy Memorial Sloan Kettering Cancer Center

Dr. Ying Taur

Loss of normal gut bacteria after allo-HSCT and antibiotics is a common occurrence and known risk factor for graft-versus-host disease (GVHD) and intestinal infection.

“Overall, patients who lose gut microbiota diversity at the time of hematopoietic stem cell engraftment have higher rates of transplant-related death,” reported Ying Taur, MD, of the Memorial Sloan Kettering Cancer Center in New York, and his colleagues. “We explored whether the microbiota could be restored in allo-HSCT patients through the use of auto-FMT.”

Allo-HSCT patients are immune suppressed for months after engraftment, so safety concerns led the investigators to use auto-FMT rather than a fecal transplant from another individual. The complex population of viruses, fungi, archaea, bacteria, and protozoa that inhabit the human gut remains poorly understood, as does the infectious potential of a heterologous fecal donor.

“Despite remarkable advances in recent years, current technologies are incapable of comprehensively determining fecal composition,” the authors wrote in Science Translational Medicine.

The study involved 25 patients undergoing allo-HSCT with intensive antibiotic therapy. Prior to engraftment, fecal samples were collected from all patients and analyzed for composition and diversity, measured by inverse Simpson index.

Samples were then frozen and stored. Fecal analysis also was performed after engraftment, and again after the auto-FMT time point. Auto-FMT was performed in 14 patients; 11 patients served as controls and did not receive treatment. Patients were followed for 1 year.

The investigators found that all of the patients who underwent auto-FMT recovered their pre–allo-HSCT microbiota composition and diversity, compared with none of the controls (P less than .0001). Further analysis showed that auto-FMT increased diversity (inverse Simpson index) by 64%, compared with 38% in controls.

“We have demonstrated the potential of auto-FMT as a clinical intervention to restore intestinal microbiota diversity to levels deemed safe in patients, thereby reversing the disruptive effects of broad-spectrum antibiotic treatment for patients undergoing allo-HSCT transplant,” the investigators concluded.

Study funding was provided by the Leonard Tow Foundation and the Memorial Sloan Kettering’s Center for Microbes, Inflammation, and Cancer. The authors reported financial relationships with Merck, AbbVie, Nektar Therapeutics, Novartis, and others.

SOURCE: Taur Y et al. Sci Transl Med. 2018 Sep 26. doi: 10.1126/scitranslmed.aap9489.

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