Bariatric Surgery, Abdominoplasty, Collagen Synthesis, Skin Physiology, Randomized Controlled Trial, Tissue Remodeling
Conditions
Keywords
Collagen, dietary supplements, bariatric surgery, body contouring, abdominoplasty, mammaplasty, wound healing, cicatrix, randomized controlled trial
Brief summary
This single-center, randomized, placebo-controlled trial evaluated whether perioperative supplementation with a collagen-based oral formulation affected dermal collagen content and postoperative outcomes in adults aged 18-65 years who had previously undergone metabolic/bariatric surgery and were scheduled for breast and/or abdominal body-contouring surgery. The active formulation (Nutribites Collageen Naturel) provided 11.8 g hydrolyzed bovine collagen peptides, 80 mg vitamin C derived from acerola, and 150 mg hyaluronic acid per daily serving; the comparator was 10 g of food-grade starch daily. Supplementation began eight weeks before surgery and was planned to continue for four weeks after surgery. Tissue was obtained only from skin routinely removed during the planned operation. The primary endpoint was dermal collagen area fraction in picrosirius-red-stained excised skin, quantified under conventional light microscopy. Secondary and other outcomes included collagen I and III immunohistochemical area fractions, epidermal thickness, TGF-beta1 and MMP-1 epidermal immunoreactivity, serum hydroxyproline, postoperative wound complications, and the study-specific modified Vancouver Scar Scale score at 3 and 6 months. Participants were recruited from 15 April to 1 October 2025. A total of 111 participants were randomized, 55 to the collagen-based formulation and 56 to placebo. Final follow-up was completed on 31 May 2026.
Interventions
DIETARY_SUPPLEMENTCollagen hydrolyzed peptides
Daily serving of Nutribites Collageen Naturel providing 11.8 g hydrolyzed bovine collagen peptides, 80 mg vitamin C derived from acerola, and 150 mg hyaluronic acid, dissolved in approximately 200 mL water. Started eight weeks before surgery and planned to continue for four weeks after surgery. The intervention is the combined commercial formulation; effects cannot be attributed to collagen peptides alone.
DIETARY_SUPPLEMENTStarch
10 g food-grade starch once daily in pre-weighed opaque sachets, dissolved in approximately 200 mL water. Started eight weeks before surgery and planned to continue for four weeks after surgery. Packaging and preparation instructions were matched to the active formulation; formal equivalence of taste and odor was not assessed.
Sponsors
General Committee of Teaching Hospitals and Institutes, Egypt
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
SUPPORTIVE_CARE
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* Patients aged 18-65 years after metabolic bariatric surgery. * Patients will be randomly selected from the hospital's electronic patient system.
Exclusion criteria
* Allergies or Sensitivities: Patients with known allergies or hypersensitivity to collagen or any components of the collagen supplements (e.g., bovine, marine sources). * 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. * 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. * 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. * 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. * Pregnancy or Lactation: Pregnant or breastfeeding women should be excluded due to the physiological changes during pregnancy and lactation that could affect collagen metabolism. * 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. * Smoking: Smokers or individuals who have recently quit smoking, as smoking is known to reduce collagen synthesis and impair skin healing. * Chronic Illnesses: Patients with chronic illnesses such as diabetes, liver disease, or kidney disease, which could impair collagen metabolism or affect skin health. * 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. * 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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Dermal collagen area fraction in routinely excised skin | At planned body-contouring surgery after eight weeks of preoperative supplementation; recorded exposure was 56-59 days among participants who underwent surgery. | Percentage of dermal area occupied by collagen in picrosirius-red-stained sections of routinely excised breast and/or abdominal skin obtained during planned body-contouring surgery. Collagen-positive area was quantified by ImageJ under conventional light microscopy in at least five non-overlapping fields within predefined dermal regions. Polarized-light images were used to describe collagen-fiber organization qualitatively, not to identify collagen types. The primary comparison was the adjusted between-group difference in dermal collagen area fraction, with anatomical site included as a fixed effect and participant as a random intercept. Specimens from different operated sites remained separate observations. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Collagen I and collagen III area fractions | At planned body-contouring surgery after eight weeks of preoperative supplementation; recorded exposure was 56-59 days among participants who underwent surgery. | Collagen I and collagen III area fractions were quantified by immunohistochemistry in corresponding dermal regions of routinely excised breast and/or abdominal skin. The collagen I:III ratio was calculated from these immunohistochemical measurements; collagen types were not assigned from polarized picrosirius-red colors. |
| Epidermal thickness | At planned body-contouring surgery after eight weeks of preoperative supplementation; recorded exposure was 56-59 days among participants who underwent surgery. | Epidermal thickness measured in H\&E-stained sections of routinely excised breast and/or abdominal skin at the time of surgery after approximately 8 weeks of supplementation; the recorded preoperative exposure was 56-59 days among participants with surgery. |
| TGF-beta1 and MMP-1 expression | At planned body-contouring surgery after eight weeks of preoperative supplementation; recorded exposure was 56-59 days among participants who underwent surgery. | Epidermal-keratinocyte immunoreactivity for TGF-beta1 and MMP-1 in routinely excised breast and/or abdominal skin was evaluated using the study-specific modified immunoreactive score. The positive-cell proportion score (0-3) was multiplied by staining intensity (0-3), yielding a score from 0 to 9. These measurements describe epidermal immunoreactivity and are not direct measures of dermal fibroblast activity. |
| Serum hydroxyproline | Baseline before supplementation and one day before planned body-contouring surgery, before surgical preparation. | Serum total hydroxyproline measured at baseline and again one day before surgery, before surgical preparation. The main comparison is the between-group difference in change from baseline. Serum hydroxyproline is a supportive systemic marker and is not the primary tissue endpoint. |
| Postoperative wound complications | From the postoperative assessment at approximately two weeks through the final assessment at six months after surgery. | Participant-level postoperative wound complications, including infection, wound dehiscence, seroma, delayed healing, reoperation, and additional antibiotic use, assessed from the postoperative visit at approximately 2 weeks through the final follow-up. Complication severity is classified using the Clavien-Dindo classification. |
Countries
Egypt
Contacts
PRINCIPAL_INVESTIGATORMohamed Hany Ashour, professor, MD
Alexandria University
Outcome results
None listed