Effects of Omega-3 Fatty Acids on Inflammation and Gut Microbiota in Celiac Disease (OMEGA-CD)

Modulation of Blood and Small Intestinal Inflammatory Processes and Fecal Microbiota in Celiac Disease Associated With the Intake of n-3 Polyunsaturated Fatty Acids

The goal of this clinical trial is to learn if omega-3 fatty acid supplements (n-3 PUFAs) can help reduce inflammation and promote intestinal healing in adults newly diagnosed with celiac disease (CD).

Celiac disease is a chronic autoimmune disorder where eating gluten-a protein found in wheat-triggers an immune response that damages the lining of the small intestine. This damage causes inflammation and symptoms such as stomach pain, diarrhea, and nutrient absorption problems. The only current treatment is a strict gluten-free diet (GFD), which can help most people recover, but some continue to have inflammation and symptoms.

This study will test whether supplementing with 2.4 grams of n-3 PUFAs daily for three months, alongside starting a gluten-free diet, reduces inflammation in the blood and intestine more effectively than the gluten-free diet alone.

Participants will:

Be adults recently diagnosed with celiac disease who have not yet started a gluten-free diet

Be randomly assigned to one of two groups:

One group will receive omega-3 supplements containing 2,400 mg of n-3 PUFAs daily (2,000 mg DHA and 400 mg EPA) The other group will receive a placebo (a pill with no active ingredients that looks like the supplement) Take the assigned supplement every day for 3 months while following a supervised gluten-free diet Visit the clinic regularly for checkups, blood tests, and monitoring of symptoms and diet adherence Provide blood and stool samples before and after the intervention to measure inflammation and changes in gut bacteria A subgroup of participants will undergo small intestinal biopsies to assess local inflammation and healing

The study aims to answer these main questions:

Does omega-3 supplementation change the fatty acid composition in blood cells? Does it reduce markers of inflammation in the blood and small intestine? Does it improve the diversity and health of gut bacteria in the intestine? Does it help the small intestine heal faster compared to diet alone?

Researchers will measure inflammation by analyzing immune signaling pathways, oxidative stress markers, and antioxidant activity in blood cells. They will also study the composition of the gut microbiota and its metabolites. These detailed measurements will help understand how omega-3 fatty acids may influence the immune response and gut health in celiac disease.

This is a randomized, double-blind, placebo-controlled crossover study. This means participants and researchers will not know who receives the supplement or placebo during the study period, reducing bias and improving the reliability of the results.

This study is important because it could offer a simple, additional treatment to improve recovery in celiac disease beyond the gluten-free diet. If omega-3 supplements are shown to reduce inflammation and support healing, they could become a valuable part of managing this chronic condition.

Participation is voluntary, and participants can leave the study at any time without affecting their medical care. All participants will be closely monitored to ensure safety throughout the study.

Study Overview

• Status: Recruiting
• Conditions: Celiac Disease
• Intervention / Treatment: Dietary supplement: n-3 Polyunsaturated Fatty Acids (PUFAs); Dietary supplement: Placebo

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Karla A Bascuñán, PhD; Phone Number: +56 2 9773232; Email: kbascunan@uchile.cl

Study Locations

• Chile
  • Metropolitan Region
    • Santiago, Metropolitan Region, Chile, 8380000
      • Recruiting
      • University of Chile Clinical Hospital
      • Contact: Paulina Toledo (Clinical Research Coordinator)+569; Phone Number: 987299944; Email: ptoledo@hcuchi.cl

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Adult patients aged 18 to 65 years, Newly diagnosed with celiac disease confirmed by serology and intestinal biopsy, Not yet started gluten-free diet (GFD), Willingness to adhere to a supervised gluten-free diet during the study, Able to provide informed consent

Exclusion Criteria:

• Previous or current adherence to a gluten-free diet, Use of n-3 PUFA supplements or other dietary supplements influencing inflammation within the last 3 months, Presence of other autoimmune, inflammatory, or gastrointestinal diseases (e.g., Crohn's disease, ulcerative colitis), Pregnancy or breastfeeding, Severe chronic illnesses that may interfere with the study or outcomes (e.g., uncontrolled diabetes, cancer), Allergy or intolerance to fish oil or components of the supplement, Use of immunosuppressive or anti-inflammatory medication within the last 3 months

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Omega-3 PUFA Supplement; Participants in this group will receive daily oral supplementation with 2,400 mg of omega-3 polyunsaturated fatty acids (2,000 mg DHA and 400 mg EPA) for 3 months. All participants will start a supervised gluten-free diet at the same time. Clinical symptoms, dietary adherence, and safety will be monitored throughout the intervention period.	Dietary supplement: n-3 Polyunsaturated Fatty Acids (PUFAs); n-3 PUFAs supplementation consisting of 2,400 mg per day (2,000 mg docosahexaenoic acid [DHA] and 400 mg eicosapentaenoic acid [EPA]), administered orally for 3 months in newly diagnosed adult celiac disease patients. The supplementation is given alongside the initiation of a gluten-free diet (GFD). The aim is to assess whether supplementation modulates the inflammatory response and supports intestinal recovery. This is part of a randomized, double-blind, placebo-controlled, crossover trial comparing supplementation versus placebo.; Other Names: Omega-3 fatty acids; DHA + EPA
Placebo Comparator: Placebo; Participants in this group will receive a daily oral placebo supplement, identical in appearance and taste to the omega-3 supplement, for 3 months. All participants will begin a supervised gluten-free diet at the same time. Clinical symptoms, dietary adherence, and safety will be monitored throughout the intervention period.	Dietary supplement: Placebo; Placebo capsules identical in appearance and taste to the active n-3 polyunsaturated fatty acid (PUFA) supplement, administered orally once daily for 3 months in newly diagnosed adult celiac disease patients. Participants will simultaneously begin a supervised gluten-free diet. This intervention serves as a control to evaluate the effect of the active supplement on modulating the inflammatory response and intestinal recovery.; Other Names: Placebo capsule; Placebo supplement

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Modulation of systemic inflammatory response via cytokine levels and NF-κB signaling in peripheral blood mononuclear cells	Levels of proinflammatory cytokines and NF-κB signaling in peripheral blood mononuclear cells will be measured to assess the reduction of systemic inflammation in newly diagnosed adult celiac patients receiving n-3 PUFA supplementation versus placebo.	From baseline (T0) to 3 months (T3) of supplementation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in fatty acid composition of erythrocyte and peripheral blood mononuclear cell membranes	The fatty acid profiles of erythrocyte and peripheral blood mononuclear cell membranes will be analyzed at baseline and after 3 months to assess the impact of n-3 PUFA supplementation on membrane lipid composition in adult celiac disease patients.	From baseline (T0) to 3 months (T3) of supplementation

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Evaluation of intestinal inflammation and microbiota composition in newly diagnosed celiac disease patients following n-3 PUFA supplementation	Assessment of local intestinal inflammation and gut microbiota changes in newly diagnosed adult celiac disease patients receiving 2.4 g/day of n-3 polyunsaturated fatty acids alongside a supervised gluten-free diet. Intestinal biopsies and fecal samples will be collected at baseline (T0) and after 3 months (T3) to measure inflammatory markers (e.g., NFκB, pro-inflammatory cytokines, I-FABP) and characterize fecal microbiota diversity and short-chain fatty acid profiles. This will determine the impact of n-3 PUFA supplementation on mucosal inflammation and the intestinal microenvironment. Time Frame:	From baseline (T0) to 3 months post-intervention (T3)

Collaborators and Investigators

• Sponsor: University of Chile
• Collaborators: Clínica Universidad de los Andes

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2025
• Primary Completion (Estimated): October 30, 2026
• Study Completion (Estimated): December 30, 2026

Study Registration Dates

• First Submitted: May 6, 2026
• First Submitted That Met QC Criteria: May 6, 2026
• First Posted (Actual): May 14, 2026

Study Record Updates

• Last Update Posted (Actual): May 14, 2026
• Last Update Submitted That Met QC Criteria: May 6, 2026
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: Celiac Disease; Omega-3 Fatty Acids; Intestinal Inflammation
• Additional Relevant MeSH Terms: Metabolic Diseases; Intestinal Diseases; Digestive System Diseases; Gastrointestinal Diseases; Malabsorption Syndromes; Nutritional and Metabolic Diseases; Celiac Disease; Fatty Acids; Lipids; Fatty Acids, Unsaturated; Oils; Dietary Fats; Fats; Dietary Fats, Unsaturated; Fish Oils; Fatty Acids, Omega-3
• Other Study ID Numbers: 11240685

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified individual participant data (IPD) collected during this study will be made available to qualified researchers upon reasonable request after publication of the primary study results. Data sharing requests will be reviewed by the study steering committee to ensure appropriate use and compliance with ethical and privacy regulations. Data will be shared through a secure data repository, and a data use agreement will be required.

Drug and device information, study documents

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