This study aims to evaluate the effects of oral collagen supplementation on dermal collagen content in skin biopsies of patients undergoing abdominoplasty. Using a randomized controlled trial (RCT) design, participants from metabolic bariatric surgery (MBS) and plastic surgery groups will receive either collagen supplements or a placebo for several weeks. Biopsies will be collected pre-intervention and during surgery to compare collagen levels between groups and to baseline. The primary objective is to determine if collagen supplementation significantly enhances dermal collagen deposition compared to placebo and initial levels.

Inclusion Criteria:

• Patients aged 18-75 years after metabolic bariatric surgery.
• Patients will be randomly selected from the hospital's electronic patient system.

Exclusion Criteria:

• 1. Allergies or Sensitivities:

  • Patients with known allergies or hypersensitivity to collagen or any components of the collagen supplements (e.g., bovine, marine sources).

    2. Chronic Skin Conditions:

  • Participants with skin disorders that could influence collagen production or degradation (e.g., psoriasis, eczema, scleroderma) should be excluded as these conditions might interfere with the study's outcomes.

    3. Autoimmune or Connective Tissue Diseases:

  • Patients with autoimmune diseases (e.g., lupus, rheumatoid arthritis) or connective tissue disorders (e.g., Ehlers-Danlos syndrome) might exhibit abnormal collagen metabolism and could confound the study's results.

    4. Use of Collagen or Nutritional Supplements:

  • Participants currently taking collagen supplements or other nutritional supplements (e.g., vitamin C, glucosamine, chondroitin) that could affect collagen synthesis or turnover should be excluded. A washout period may be required for those who have recently used such supplements.

    5. Hormonal Treatments or Medications:

  • Patients on treatments that could affect collagen metabolism (e.g., corticosteroids, hormone replacement therapy, anabolic steroids) should be excluded, as these could alter the body's collagen production or degradation.

    6. Pregnancy or Lactation:

  • Pregnant or breastfeeding women should be excluded due to the physiological changes during pregnancy and lactation that could affect collagen metabolism.

    7. Major Surgeries or Trauma:

  • Recent major surgeries or significant trauma within the last 6-12 months, especially those involving connective tissue repair, as these could alter collagen levels independently of supplementation.

    8. Smoking:

  • Smokers or individuals who have recently quit smoking, as smoking is known to reduce collagen synthesis and impair skin healing.

    9. Chronic Illnesses:

  • Patients with chronic illnesses such as diabetes, liver disease, or kidney disease, which could impair collagen metabolism or affect skin health.

    10. Uncontrolled Metabolic Disorders:

  • Participants with uncontrolled metabolic disorders (e.g., severe obesity, untreated hyperlipidemia) may have altered collagen metabolism and should be excluded unless specifically studied.

    11. Participation in Other Clinical Trials:

  • Patients currently enrolled in other clinical trials involving supplements, medications, or procedures that could interfere with the study outcomes should be excluded.

The analysis will be performed on a blinded dataset after completing the medical/scientific review. All protocol violations will be identified and resolved, and the dataset will be declared complete. All data will be collected in a data management system (Castor EDC, Amsterdam, The Netherlands; https://www.castoredc.com), handled according to Good Clinical Practice guidelines, Data Protection Directive certificate, and complied with Title 21 CFR Part 11. Furthermore, the data centers where all the research data will be stored are certified according to ISO27001, ISO9001, and Dutch NEN7510

Available at PI for protocol and SAP ICF, CSR and analytic code after study completion

Available at PI