Transplant Research and Risk Management (Sep 2021)

Changes in the Composition and Function of the Human Salivary Microbiome After Heart Transplantation: A Pilot Study

  • Joyce H,
  • Taylor MR,
  • Moffat A,
  • Hong M,
  • Isaac D,
  • Fine N,
  • Greenway SC

Journal volume & issue
Vol. Volume 13
pp. 15 – 21

Abstract

Read online

Heidi Joyce,1 Michael R Taylor,1 Andrew Moffat,1 Mia Hong,1 Debra Isaac,2 Nowell Fine,2 Steven C Greenway1– 3 1Department of Pediatrics and Alberta Children’s Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; 2Department of Cardiac Sciences and Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; 3Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, CanadaCorrespondence: Steven C GreenwaySection of Cardiology, Alberta Children’s Hospital, 28 Oki Drive NW, Calgary, AB, T3B 6A8, CanadaTel +1-403-955-5049Fax +1-403-955-7621Email [email protected]: Interactions between our commensal microbes and immune system are well recognized but the impact of immunosuppression on this relationship is less well characterized, particularly outside of the gastrointestinal tract. In this pilot case-control study, we examined microbial composition and inferred function in the saliva of patients after heart transplantation.Methods: Saliva samples were collected from 26 healthy adolescent and adult heart transplant patients and 27 healthy non-transplant controls. Bacterial DNA was isolated and the V3 and V4 regions of the 16S rRNA gene were sequenced. Measures of bacterial diversity and inferred function were calculated using the software packages DADA2, Phyloseq, QIIME, PICRUSt and STAMP.Results: Transplant patients were on average 51.6 ± 18.2 years of age and 8.6 ± 5.3 years post-transplant. Both alpha (p = 0.0009) and beta (p = 0.001) diversity differed significantly between the groups, and there were statistically significant changes (p < 0.01) in 101 individual functional pathways.Discussion: We conclude that the effects of chronic immunosuppression on bacterial composition and function in the oropharynx appear relatively subtle with no obvious ill effects on patient health. Full interpretation is limited by our lack of knowledge for many of the bacterial functional pathways.Keywords: microbiome, saliva, transplant, heart, immune suppression

Keywords