Recruiting
Phase 3

Fiber & Metformin

Sponsor:

University of Alberta

Code:

NCT04578652

Conditions

Obesity, Childhood

Insulin Resistance

Eligibility Criteria

Sex: All

Age: 12 - 18

Healthy Volunteers: Not accepted

Interventions

Metformin 850 mg oral tablet bid

Supplemental fiber mixture (35 g total) composed of 6g of Oligofructose + 12g of resistant maltodextrin + 12g of acacia gum + 5g of PGX.

Study Details

Brief summary:

This is a 12-month, single center, three-arm parallel design, double-blind, randomized clinical trial, to compare the effects of supplemental dietary fiber and metformin (MET) alone and in combination over 12 months on glucose metabolism (insulin resistance \[IR\]), inflammation and BMI in adolescents with obesity and IR, and to assess the relationship between therapeutic intervention(s) and changes in gut microbiome composition and function.

Since MET and FIBER have been shown to reduce weight and increase insulin sensitivity through distinct but overlapping mechanisms of action, our central hypothesis is that the combination of FIBER + MET will have a synergistic effect and be more effective than FIBER or MET alone in improving metabolic function (IR) and reducing BMI and inflammation in adolescents with obesity, IR and family history (FM) of T2DM.

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Conditions

Obesity, Childhood

Insulin Resistance

Study ID

NCT04578652

Start date

Oct 22, 2021

Status verified date

Nov, 2025

Completion date

Sep, 2026

Anticipated

Primary completion date

Sep, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 12 - 18

Healthy Volunteers: Not accepted

Inclusion Criteria:

1. Age 12-18 years
2. BMI percentile > 95% for age/sex;
3. Total weight fluctuation over past 6 months < 10%;
4. HOMA-IR > 3.16;
5. FH of T2DM (first or second-degree relative).

Exclusion Criteria:

1. Current use of insulin or diagnosis of T2DM;
2. Systolic or diastolic blood pressure (BP) > 99th percentile for age and sex;
3. Acute infectious or inflammatory condition over the preceding 1 month; hospitalization > 48 hrs;
4. History of chronic disease such as inflammatory bowel disease, chronic severe liver or kidney disease or neurologic disorders;
5. Active malignancy;
6. Concomitant use of medication/investigational drug known to affect body weight in the past year;
7. Antibiotic use in past 60 days; probiotic and/or prebiotic supplements use in the past 30 days; use of lipid-lowering and anti-inflammatory medication.

Study Design

Enrollment

90 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

active comparator: MET

MET (850 mg po bid - standard of care) + Fiber placebo daily

active comparator: FIBER

Fiber supplementation \[35g fiber daily\] + MET placebo po bid

experimental: FIBER + MET

Fiber supplementation \[35g fiber daily\] + MET 850 mg po bid

Interventions

Metformin 850 mg oral tablet bid

MET dose: 500 mg daily, increasing to 500 bid if tolerated after 2 weeks, then increasing again 2 weeks later to 850 mg bid (1700 mg daily).

Supplemental fiber mixture (35 g total) composed of 6g of Oligofructose + 12g of resistant maltodextrin + 12g of acacia gum + 5g of PGX.

The first week of treatment will use 1/3 the daily treatment dose; then 2/3 dose for the second and third weeks; then the full dose thereafter, to allow time for adaptation.

Primary outcome measure

  • Changes in HOMA-IR [ Time Frame: Baseline, 6, and 12 months ]

Central Contacts and Locations

Central contacts

Andrea M Haqq, MD, MHS

780-492-0015haqq@ualberta.ca

Locations

University of Alberta

Recruiting

Edmonton, Alberta, Canada, T6G 2E1

Contacts

Andrea M Haqq, MD, MHS

780-492-0015haqq@ualberta.ca

Principal Investigator:

Andrea M Haqq, MD, MHS

More Information

Sponsor

University of Alberta

Last update posted

Nov 17, 2025

Last verified

Nov, 2025

Keywords

  • Dietary fiber
  • Metformin

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of Alberta on 2025-11-17.