First insights into the microbiome of leaks following foregut surgery

Anastomotic leaks are a devastating complication of foregut surgery that can be managed surgically or endoscopically. Studies show that the pathogenesis of leaks is influenced by gut microbiomes. We seek to delineate outcome differences in patients who were successfully managed endoscopically versus those who required surgery and compare differences in microbiome composition.

An institutional review board-approved, prospectively maintained database was retrospectively reviewed for patients with foregut leaks from 2021 to 2024. Primary end points were endoscopic-only management or surgery. Other variables include readmissions, interventions, bloodwork, and American College of Surgeons surgical risk. During therapeutic interventions, microbial and host samples were collected. For the first 16 patients, the DNA samples were extracted, amplified, sequenced, and clustered into operational units for analysis.

Of the 38 patients with leaks, 92% were managed endoscopically, whereas 8% required surgery. Of the endoscopic group, 26% healed with endoluminal vacuum therapy, 9% with stent, 23% with an endoluminal drain, and 42% with a combination. The surgery group had a lower albumin level (P = .04) and longer preoperative predicted length of stay (P = .03). Bacterial composition shifted with each intervention. There were 4 main bacteria-Firmicutes, Bacteroides, Actinobacteria, and Proteobacteria. In the endoscopic-only group, Bacteroides and Firmicutes predominated. One surgical patient had a comparatively higher ratio of Proteobacteria.

Patients who failed endoscopic management had poorer nutrition and higher preoperative risk factors, which may contribute to an unfavorable microbial composition that inhibits wound healing. Understanding the gut microbiome in gastrointestinal leaks could lead to more effective prevention and treatment strategies.