V. T. Daniel1, D. V. Ward2, C. I. Kiefe3, B. A. McCormick2, H. P. Santry4
1University Of Massachusetts Medical School,Department Of Surgery,,Worcester, MA, USA 2University of Massachusetts Medical School,Center For Microbiome Research,Worcester, MA, USA 3University Of Massachusetts Medical School,Department of Quantitative Health Sciences,,Worcester, MA, USA 4The Ohio State University Wexner Medical Center,Department Of Surgery,Columbus, OHIO, USA
Introduction: Although many pro-inflammatory conditions have been shown to have decreased microbiome diversity (alpha) as well as dysbiosis, little is known about the gut microbiome of patients with gastrointestinal perforations with inflammatory etiologies. In addition, it is unclear whether gut dysbiosis plays a role in the development of poor outcomes of surgical patients. Therefore, the objective of our study was to prospectively evaluate outcomes of patients with gastrointestinal perforations who underwent surgical intervention, to characterize the microbiome of these patients, and to assess the alpha diversity of these patients who develop poor outcomes.
Methods: Patients with stomach, small intestine, and large intestine perforations who underwent surgical intervention at a single institution were included in this prospective, translational study. 16srRNA gene sequences extracted from swabs at the perforation site were analyzed and then the reads were clustered and classified to microbial genome using QIIME. Specific taxonomic abundances were assessed. Analysis of composition of microbiomes (ANCOM) was used to assess differences of alpha diversity within groups. Outcomes assessed were 30-day mortality, 30-day postoperative sepsis, and all-cause 30-day readmission rate.
Results: Interim analysis demonstrated overall 28 subjects with stomach (18%), small intestine (36%), and large intestine (46%) perforations underwent surgical intervention. The majority were males (68%) with a mean age of 66 years (SD 16 years) who were not smokers (71%) nor used steroids (86%). The 30-day mortality rate was 14% and postoperative sepsis rate was 50%. 30-day readmission rate was 11%. Bacteroidetes dominated the gut microbiome of patients with gastrointestinal perforations. Although not significant, microbiome alpha diversity was lower for the following groups: those who died within 30 days postoperatively compared to those who did not (p=0.59), those with postoperative sepsis compared to those without (p=0.76), and those who were readmitted within 30 days compared to those who were not (p=-.67).
Conclusion: In our small sample size, we did not find any significant differences in microbiome alpha diversity among patients with gastrointestinal perforations who had poor postoperative outcomes; however these preliminary data demonstrate high mortality among those with gastrointestinal perforations and suggest possible similarities between gut microbiome of patients with gastrointestinal perforations. Further research is needed to better characterize the microbiome of a larger sample of patients with gastrointestinal perforations compared to controls, and furthermore, those with gastrointestinal perforations who develop poor outcomes.