DO PERIOPERATIVE SYNBIOTICS REDUCE TOTAL POSTOPERATIVE INFECTION RATES FOLLOWING ELECTIVE COLORECTAL RESECTION? A RANDOMIZED CONTROLLED TRIAL. claudia.paterson@auckland.ac.nz

411-03

DO PERIOPERATIVE SYNBIOTICS REDUCE TOTAL POSTOPERATIVE INFECTION RATES FOLLOWING ELECTIVE COLORECTAL RESECTION? A RANDOMIZED CONTROLLED TRIAL.

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Wal Baraza wal.baraza@auckland.ac.nz University of Auckland Department of Surgery Auckland New Zealand

Parry Singh parry.singh@middlemore.co.nz University of Auckland Department of Surgery Auckland New Zealand

Andrew Hill a.hill@auckland.ac.nz University of Auckland Department of Surgery Auckland New Zealand

New Zealand

Oral or Poster

Emerging evidence suggests that the gut microbiota may contribute to the development of postoperative infections following elective colorectal resection, and may serve as a target for intervention. This study aimed to investigate the efficacy of a perioperative synbiotic (probiotic + prebiotic) regimen on total postoperative infection rates within 30 days of surgery.

A double-blinded, superiority 1:1 randomized controlled trial (RCT) was conducted across three New Zealand public hospitals between June 2024 and July 2025. Eligible participants were adults undergoing elective colorectal resection for any indication, with an anastomosis and a portion of colon remaining in-situ postoperatively. Exclusion criteria included acute surgery, probiotic intolerance, patient refusal, acute pancreatitis, and severe immunosuppression. Hospital sites were stratified to account for variations in mechanical bowel preparation and oral antibiotic protocols. Participants received either a synbiotic powder or maltodextrin placebo once daily for 7 days preoperatively and 14 days postoperatively. The primary outcome was total postoperative infection rates within 30 days of surgery.

Of the 209 participants randomised, 165 remained in the study postoperatively. The median age of participants was 65 years, and 53.9% were male. Malignant indications for surgery were present in 73.9% of cases. All participants had undergone surgery by 31 July 2025, and all participants will have completed the 30-day follow period by 31 August 2025.

This is the first RCT in Australasia to assess the efficacy of a perioperative synbiotic regimen on postoperative infections following elective colorectal resection. Findings will be available after 31 August 2025.