Gut microbiota profiles and fecal beta-glucuronidase activity in kidney transplant recipients with and without post-transplant diarrhea

Clin Transplant. 2021 May;35(5):e14260. doi: 10.1111/ctr.14260. Epub 2021 Mar 9.


Post-transplant diarrhea is a common complication after solid organ transplantation and is frequently attributed to the widely prescribed immunosuppressant mycophenolate mofetil (MMF). Given recent work identifying the relationship between MMF toxicity and gut bacterial β-glucuronidase activity, we evaluated the relationship between gut microbiota composition, fecal β-glucuronidase activity, and post-transplant diarrhea. We recruited 97 kidney transplant recipients and profiled the gut microbiota in 273 fecal specimens using 16S rRNA gene sequencing. We further characterized fecal β-glucuronidase activity in a subset of this cohort. Kidney transplant recipients with post-transplant diarrhea had decreased gut microbial diversity and decreased relative gut abundances of 12 genera when compared to those without post-transplant diarrhea (adjusted p value < .15, Wilcoxon rank sum test). Among the kidney transplant recipients with post-transplant diarrhea, those with higher fecal β-glucuronidase activity had a more prolonged course of diarrhea (≥7 days) compared to patients with lower fecal β-glucuronidase activity (91% vs 40%, p = .02, Fisher's exact test). Our data reveal post-transplant diarrhea as a complex phenomenon with decreased gut microbial diversity and commensal gut organisms. This study further links commensal bacterial metabolism with an important clinical outcome measure, suggesting fecal β-glucuronidase activity could be a novel biomarker for gastrointestinal-related MMF toxicity.

Keywords: diarrhea; gut microbiota; kidney transplantation; mycophenolate mofetil.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Diarrhea
  • Gastrointestinal Microbiome*
  • Glucuronidase
  • Humans
  • Kidney Transplantation*
  • RNA, Ribosomal, 16S


  • RNA, Ribosomal, 16S
  • Glucuronidase