title: Intestinal anastomotic injury alters spatially defined microbiome composition and function.
abstract: BACKGROUND
  When diseased intestine (i.e., from colon cancer, diverticulitis) requires resection, its reconnection (termed anastomosis) can be complicated by non-healing of the newly joined intestine resulting in spillage of intestinal contents into the abdominal cavity (termed anastomotic leakage). While it is suspected that the intestinal microbiota have the capacity to both accelerate and complicate anastomotic healing, the associated genotypes and functions have not been characterized.
  
  
  RESULTS
  Using 16S rRNA amplicon sequencing of samples collected on the day of surgery (postoperative day 0 (POD0)) and the 6th day following surgery (postoperative day 0 (POD6)), we analyzed the changes in luminal versus tissue-associated microbiota at anastomotic sites created in the colon of rats. Results indicated that anastomotic injury induced significant changes in the anastomotic tissue-associated microbiota with minimal differences in the luminal microbiota. The most striking difference was a 500-fold and 200-fold increase in the relative abundance of Enterococcus and Escherichia/Shigella, respectively. Functional profiling predicted the predominance of bacterial virulence-associated pathways in post-anastomotic tissues, including production of hemolysin, cytolethal toxins, fimbriae, invasins, cytotoxic necrotizing factors, and coccolysin.
  
  
  CONCLUSIONS
  Taken together, our results suggest that compositional and functional changes accompany anastomotic tissues and may potentially accelerate or complicate anastomotic healing.
authors.affiliation: Department of Surgery, University of Chicago, 5841 S. Maryland, Chicago, IL 60637, USA.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Shogan
authors.affiliation: Institute for Genomic and Systems Biology, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA ; Current address: Center for Metagenomics and Microbiome Research, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Smith
authors.affiliation: Department of Surgery, University of Chicago, 5841 S. Maryland, Chicago, IL 60637, USA.
authors.forename: Scott
authors.initials: S
authors.lastname: Christley
authors.affiliation: Institute for Genomic and Systems Biology, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA ; Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Jack A
authors.initials: JA
authors.lastname: Gilbert
authors.affiliation: Department of Surgery, University of Chicago, 5841 S. Maryland, Chicago, IL 60637, USA.
authors.forename: Olga
authors.initials: O
authors.lastname: Zaborina
authors.affiliation: Department of Surgery, University of Chicago, 5841 S. Maryland, Chicago, IL 60637, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Alverdy
keywords: 16S rRNA; Anastomotic tissues; Bacterial composition; Colon anastomosis; Luminal content; PiCRUST; Predicted function