Impact of an Omega-3 Enriched Oral Nutritional Supplement on Improving Surgical Outcomes in Patients With Peritoneal Carcinomatosis Undergoing Cytoreductive Surgery (OMNI)

Impact of an Omega-3 Enriched Oral Nutritional Supplement on Improving Surgical Outcomes in Patients With Peritoneal Carcinomatosis Undergoing Cytoreductive Surgery: A Pilot, Prospective, Randomized, Double-Blind, Controlled Study

The OMNI study is a clinical trial investigating whether a nutritional supplement with added Omega-3 fatty acids can improve surgical outcomes for patients with peritoneal carcinomatosis. Peritoneal carcinomatosis is a type of cancer that affects the abdominal lining and often requires complex and extensive surgery called cytoreductive surgery (CRS). This procedure is associated with a high risk of postoperative complications, such as infections and long hospital stays. Omega-3 fatty acids are known for their anti-inflammatory and immune-modulating properties.

The study's main goal is to see if a 21-day regimen of a pre-operative Omega-3 enriched oral nutritional supplement (ONS) can reduce postoperative complications, as measured by the Clavien-Dindo classification.

Who can participate?

The study is recruiting patients over 18 years old who have been diagnosed with non-gynecological peritoneal carcinomatosis and are scheduled to undergo cytoreductive surgery and HIPEC (hyperthermic intraperitoneal chemotherapy).

What does participating involve?

Upon joining the study, participants will be randomly assigned to one of two groups:

• Intervention Group: Participants will receive an Omega-3 enriched nutritional supplement called Fortimel Forticare.
• Control Group: Participants will receive a standard nutritional supplement called Fortimel Compact Protein.

Both groups will be asked to consume two bottles of their assigned supplement per day for 21 days before the scheduled surgery.

What will be measured?

Throughout the study, the investigators will perform various assessments to monitor participant health and recovery:

• Before and after surgery: The investigators will take body measurements, conduct a bioimpedance analysis (BIA) to check body composition, and perform a Hand Grip test to measure muscle strength. The investigators will also collect blood and stool samples.
• During surgery: The investigators will collect tissue samples to study the tumor environment.
• After surgery: The investigators will track patient recovery, including the length of the hospital stay and any complications that may occur. The investigators will also continue to monitor certain markers in the patients' blood.

The study is expected to enroll a total of 28 patients.

Study Overview

• Status: Not yet recruiting
• Conditions: Cytoreductive Surgery; HIPEC; Peritoneal Metastases; Peritoneal Carcinosis
• Intervention / Treatment: Dietary supplement: ONS enriched with Omega-3; Dietary supplement: Standard ONS

• Study Type: Interventional
• Enrollment (Estimated): 28
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Marco Cintoni, MD; Phone Number: +39 0630154365; Email: marco.cintoni@unicatt.it

Study Locations

• Italy
  • Roma, Italy, 00168
    • Clinical Nutrition Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS
    • Contact: Marco Cintoni, MD; Phone Number: +39 0630154365; Email: marco.cintoni@unicatt.it
    • Principal Investigator: Maria Cristina Mele, MD
    • Sub-Investigator: Marco Cintoni, MD
    • Sub-Investigator: Federica Ferracci, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age > 18 years
• Diagnosis of peritoneal carcinomatosis from a non-gynecological primary neoplasm
• Patients who must undergo cytoreductive surgery and HIPEC
• Signed informed consent form

Exclusion Criteria:

• Patients with an enterocutaneous fistula
• Patients with known food allergies
• Age < 18 years
• Patients with severe organ damage (e.g., kidney failure, liver failure)
• Refusal to sign the informed consent form

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: ONS enriched with Omega-3; This group receives an ONS enriched with Omega-3, 2 bottles per day for 21 days before surgery	Dietary supplement: ONS enriched with Omega-3; 300 kcal, 18.25 g protein, 12 g lipids, ω6/ω3 ratio 0.65, 1465 mg ω3 per bottle
Active Comparator: Standard ONS; This group receives a standard ONS, 2 bottles per day for 21 days before surgery	Dietary supplement: Standard ONS; 300 kcal, 18.25 g protein, 12 g lipids, ω6/ω3 ratio 5.07 per bottle

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Number of Participants with Postoperative Complications as Assessed by Clavien-Dindo Classification	Frome the surgical intervention to 60-days after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Evaluation of variations in serum levels of specific inflammatory cytokines (IL-6, IL-10, and TNF-alpha)	Cytokines will be measured with ELLA	From baseline (1 day before surgery) up to 7 days after surgery
Evaluation of targeted metabolomic changes in blood (including amino acids, bile acids, and biogenic amines)	Assessed by the MxP® Quant 500 XL kit. This measurement quantifies over 1,000 metabolites and lipids via mass spectrometry	From enrollment (T0) to the day before surgery (T1), an estimated period of 21 days
Evaluation of changes in gut microbiota composition and diversity, assessed via 16S rRNA gene sequencing of stool samples.	The analysis will evaluate changes in microbial alpha-diversity (e.g., Shannon index), beta-diversity, and the relative abundance of specific bacterial taxa.	From enrollment (T0) to the day before surgery (T1), an estimated period of 21 days
Compliance with prescribed ONS (percentage of ONS taken of the total prescribed)		From enrollment to the day before surgery
Changes in the Tumor Microenvironment Assessed by Transcriptomic Analysis		From the enrollment (T0) to the Cytoreductive Surgery + Hipertermic Intraperitoneal Chemotherapy (T1)

Collaborators and Investigators

• Sponsor: Catholic University of the Sacred Heart
• Collaborators: Fondazione Policlinico Universitario Agostino Gemelli IRCCS; European Society for Clinical Nutrition and Metabolism

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2026
• Primary Completion (Estimated): April 1, 2028
• Study Completion (Estimated): October 1, 2028

Study Registration Dates

• First Submitted: November 17, 2025
• First Submitted That Met QC Criteria: March 13, 2026
• First Posted (Actual): March 17, 2026

Study Record Updates

• Last Update Posted (Actual): March 17, 2026
• Last Update Submitted That Met QC Criteria: March 13, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Fatty Acids; Lipids; Fatty Acids, Unsaturated; Oils; Dietary Fats; Fats; Fatty Acids, Omega-3; Dietary Fats, Unsaturated; Fish Oils; Docosahexaenoic Acids
• Other Study ID Numbers: ID 7814

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No