Preparing the Bowel (Microbiome) for Surgery: Surgical Bioresilience

Abstract

The preparation of the bowel for radical surgery is a corner stone of elective colorectal practice. The evidence for this intervention is of variable quality and it is often contradictory, yet there is now a global move toward the adoption of oral antibiotic therapy for the reduction of perioperative infective complications, such as surgical site infections. The gut microbiome is a critical mediator of the systemic inflammatory response to surgical injury, wound healing, and perioperative gut function. The loss of critical microbial symbiotic functions caused by bowel preparation and surgery has an adverse impact on surgical outcomes, yet the mechanisms through which this occurs are poorly defined. In this review, the evidence for bowel preparation strategies is critically appraised in the context of the gut microbiome. The impact of antibiotic therapy on the surgical gut microbiome and the importance of the intestinal “resistome” to surgical recovery is described. Data to support the augmentation of the microbiome through diet, probiotic and symbiotic approaches, as well as fecal transplantation are also appraised. Finally, we propose a novel strategy of bowel preparation defined as “surgical bioresilience” and define areas or prioritization in this emerging field. This describes the optimization of surgical intestinal homeostasis and core surgical exposome-microbiome interactions that regulate the wound immune microenvironment, the systemic inflammatory response to surgical injury, and gut function across the perioperative time course.

The Impact of Surgical Bowel Preparation on the Microbiome in Colon and Rectal Surgery

“…The current body of clinical evidence regarding the effect of bowel preparation on the microbiome in colorectal surgery is expanding. However, conflicting results have hindered the formation of a clear consensus on targeted interventions for patient care [94]. Another challenge in detecting the effect of microbiome changes on patient outcomes arises from the overall low event rates of complications such as anastomotic leaks and surgical site infections in colorectal surgery.…”

Probiotics and postoperative infections in colorectal surgery – what New Zealand and Australian surgeons need to know about this emerging field

“…An interesting new term is 'surgical bioresilience', which describes the concept of optimizing the gut microbiota before surgery, by encouraging microbial diversity. 11 A recent systematic review and meta-analysis from our group found that perioperative probiotics/synbiotics were associated with a significant reduction in postoperative infections following elective colorectal resection (RR 0.55, 95% CI 0.14 to 0.74, P < 0.0001). 12 However, we found major heterogeneity in perioperative regimens among included randomized controlled trials (RCTs).…”

“…Postoperative infections include SSIs as well as non‐SSIs such as pneumonia or urinary tract infections. An interesting new term is ‘surgical bioresilience’, which describes the concept of optimizing the gut microbiota before surgery, by encouraging microbial diversity 11 …”