Obesity, MorbidSLIM - Part 3NCT05471037
Different Limb Lengths in Gastric Bypass Surgery (SLIM) - Part 3: Metabolism and Inflammation
A study testing Long Biliopancreatic Limb LRYGB and Short Biliopancreatic Limb LRYGB in people with Obesity, Morbid, run by University Hospital, Basel, Switzerland at 1 site in Switzerland.
Trial summary
Investigation of underlying metabolic mechanisms and impact on the two surgical procedures on inflammatory factors. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Obesity, Morbid
- What is being tested?
- Long Biliopancreatic Limb LRYGB and Short Biliopancreatic Limb LRYGB
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 65 participants
- Where
- 1 siteSwitzerland
- Study dates
- 1 Aug 2022to 1 Oct 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 2 x 25 patients with morbid obestiy (BMI of 35 kg/m2 or higher) who comply with the regulatory rules for bariatric surgery in Switzerland (SMOB guidelines) and participate in the SLIM Trial
- 15 healthy lean controls
Who cannot join
- general contraindications to kind of surgery
- known or suspected non-compliance
- inability to follow the procedures of the study, e.g. due to language problems, psychological disorders etc. of the participant
- participation in another interventional study
- BMI > 60 kg/m2
- height < 145 cm
Show all 23Show fewer
- CL length of < 180 cm as measured intraoperatively
- ASA physical status classification > III
- inflammatory bowel disease
- diabetes
- intake of corticosteroids, anti-inflammatory/ immunosuppressive drugs potentially altering immune cells
- clinical signs of current infection
- known anemia (e.g. hemoglobin < 110g/L for males, < 100g/L for females)
- known neutropenia (e.g. leucocyte count < 1.5 x 10^9/L or ANC < 0.5 x 10^9/L)
- known immunodeficiency, e.g. HIV
- known vasculitis, collagenosis
- known adrenal insufficiency and/or substitution with glucocorticoids
- risky daily alcohol consumption (> 24g/d for males, > 12g/d for females)
- drug abuse
- known liver cirrhosis Child B or C
- known uncontrolled congestive heart failure
- known uncontrolled malignant disease
- currently pregnant or breastfeeding
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Swiss Multicenter Randomized Controlled Trial on Different Limb Lengths in Gastric Bypass Surgery (SLIM Trial) - Part 3: Metabolic Mechanisms and Inflammatory Response
Investigation of underlying metabolic mechanisms and impact on the two surgical procedures on inflammatory factors.
Read the detailed description
The aim of this project is to investigate underlying metabolic mechanisms in a subpopulation of patients of the SLIM trial, where a laparoscopic proximal Roux-en-Y gastric bypass (LRYGB) with a longer biliopancreatic limb (BPL) is compared to a standard LRYGB. For this purpose, the aim is to examine differences in number of intestinal enteroendocrine cells, subpopulations of intestinal macrophages, and gene expression or DNA-methylation in tissue samples obtained by colonoscopy from the ileum and transverse colon. In addition, gut microbiota (from colon biopsy and fecal samples), meal-stimulated gut hormone profiles, glycemic control, and metabolite patterns (metabolomics; in blood, urine, stool and breath) including plasma bile acid concentrations preoperatively and 6 months post-surgery will be examined. Body composition (fat mass and lean mass) will be measured by means of BIA (bioimpedance analysis; Biacorpus).
- Conditions
- Obesity, Morbid
- Being tested
- Long Biliopancreatic Limb LRYGB, Short Biliopancreatic Limb LRYGB
- Medical subject headings
- Obesity, Morbid
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Long Biliopancreatic Limb LRYGBProcedure or surgery
LRYGB with an 180 cm biliopancreatic limb (BPL) and an alimentary limb (AL) of 80 cm.
Short Biliopancreatic Limb LRYGBProcedure or surgery
Standard LRYGB with a 80 cm BPL and a 180 cm long AL.
| Study group | Role | What they receive |
|---|---|---|
| Long Biliopancreatic Limb LRYGB | Active comparator | 25 morbidly obese patients undergoing gastric bypass surgery, participating in SLIM Trial. Receives: Procedure: Long Biliopancreatic Limb LRYGB |
| Short Biliopancreatic Limb LRYGB | Active comparator | 25 morbidly obese patients undergoing gastric bypass surgery, participating in SLIM Trial. Receives: Procedure: Short Biliopancreatic Limb LRYGB |
| Control | No intervention | 15 normal weight control group without surgery. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in glucose tolerance
Change in glucose tolerance as measured by plasma glucose concentrations at 120 minutes after ingestion of a standardized liquid test meal, pre-OP and 6-8 months post-OP.
Measured: pre-OP and 6-8 months post-OP
Secondary outcomes (35)
glycemic control
Change in glucose variability measured by continuous glucose measurement over 1 week, pre-OP and 6-8 months post-OP.
Measured: pre-OP and 6-8 months post-OP
intestinal glucose absorption rate
Differences in intestinal glucose absorption rate after ingestion of a standardized liquid test meal measured by 3-OMG
Measured: pre-OP and 6-8 months post-OP
gastrointestinal peptides
Differences in the release of gastrointestinal peptides after ingestion of a standardized liquid test meal
Measured: pre-OP and 6-8 months post-OP
intestinal enteroendocrine cells
Differences in number and phenotype (protein expression) of intestinal enteroendocrine cells (from ileum biopsies)
Measured: pre-OP and 6-8 months post-OP
intestinal macrophages
Differences in the number and phenotype (gene expression, methylation) of intestinal macrophages and subpopulations (from colon biopsies)
Measured: pre-OP and 6-8 months post-OP
gut microbiota composition
Differences in gut microbiota composition (from colon biopsy and fecal sample)
Measured: pre-OP and 6-8 months post-OP
bile acids
Differences in bile acids and metabolomic patterns (blood)
Measured: pre-OP and 6-8 months post-OP
inflammatory profile
Differences in inflammatory profile measured by hsCRP in blood
Measured: pre-OP and 6-8 months post-OP
enterocyte gene expression
Differences in enterocyte gene expression or DNA-methylation (tissue samples from ileum biopsies)
Measured: pre-OP and 6-8 months post-OP
appetite-related sensations
Differences in subjective appetite-related sensations (feelings of hunger, prospective food consumption, satiation and fullness) after liquid test meal, assessed with Visual Analog Scales
Measured: pre-OP and 6-8 months post-OP
body composition
Body composition (measured by Bio Impedance Analysis (BIA))
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 1
Differences in mineral metabolism parameter (creatinine) in blood samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 2
Differences in mineral metabolism parameter (phosphate) in blood samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 3
Differences in mineral metabolism parameter (calcium) in blood samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 4
Differences in mineral metabolism parameter (magnesium) in blood samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 5
Differences in mineral metabolism parameter (parathyroid hormone) in blood samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 6
Differences in mineral metabolism parameter (calcidiol) in blood samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 7
Differences in mineral metabolism parameter (calcitriol) in blood samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 8
Differences in mineral metabolism parameter (FGF23) in blood samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 9
Differences in mineral metabolism parameter (desoxypyridinoline) in blood samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 10
Differences in mineral metabolism parameter (bone alkaline phosphatase (bALP)) in blood samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 11
Differences in mineral metabolism parameter (osteocalcin) in blood samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 12
Differences in mineral metabolism parameter (sclerostin) in blood samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 13
Differences in mineral metabolism parameter (P1NP) in blood samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 14
Differences in mineral metabolism parameter (CTX) in blood samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (stool) 1
Differences in mineral metabolism parameter (phosphate) in feces samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (stool) 2
Differences in mineral metabolism parameter (calcium) in feces samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (stool) 3
Differences in mineral metabolism parameter (magnesium) in feces samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (urine) 1
Differences in mineral metabolism parameter (creatinine) in urine samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (urine) 2
Differences in mineral metabolism parameter (phosphate) in urine samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (urine) 3
Differences in mineral metabolism parameter (calcium) in urine samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (urine) 4
Differences in mineral metabolism parameter (magnesium) in urine samples.
Measured: pre-OP and 6-8 months post-OP
mineral metabolism (urine) 5
Differences in mineral metabolism parameter (desoxypyridinoline) in urine samples.
Measured: pre-OP and 6-8 months post-OP
metabolomic patterns
Differences in metabolomic patterns assed in blood sample, urine sample, stool sample and exhaled breath.
Measured: pre-OP and 6-8 months post-OP
immune response
Differences in immune response biomarkers in blood measured by a cytokine screening assay
Measured: pre-OP and 6-8 months post-OP
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Jul 2022
- Study start1 Aug 2022
- Primary completion1 Oct 2026 (estimated)
- Study completion1 Oct 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Obesity, MorbidStudies of the same condition, open and under way.
- More trials run by University Hospital, Basel, SwitzerlandThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 65 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Hospital, Basel, Switzerland
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Anne Christin Meyer-Gerspach, PD Dr. phil. II Dr. habil., Principal investigator, St. Clara Forschung AG / St. Claraspital AGBettina Wölnerhanssen, PD Dr. med., Principal investigator, St. Clara Forschung AG / St. Claraspital AG
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05471037
- Sponsor's protocol ID
- SLIM - Part 3
- Acronym
- SLIM - Part 3
- Status last verified
- Apr 2026
- First submitted
- 21 Mar 2022
- Last updated
- 29 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 29 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Swiss Multicenter Randomized Controlled Trial on Different Limb Lengths in Gastric Bypass Surgery (SLIM Trial) - Part 3: Metabolic Mechanisms and Inflammatory Response
- ClinicalTrials.gov ID
- NCT05471037
- Acronym / sponsor ID
- SLIM - Part 3 / SLIM - Part 3
- Conditions
- Obesity, Morbid
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 65 participants (estimated)
- Lead sponsor
- University Hospital, Basel, SwitzerlandUniversity, hospital or other
- Study start
- 1 Aug 2022 (actual)
- Primary completion
- 1 Oct 2026 (estimated)
- Study completion
- 1 Oct 2026 (estimated)
- First posted
- 22 Jul 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Investigation of underlying metabolic mechanisms and impact on the two surgical procedures on inflammatory factors.
Detailed description
The aim of this project is to investigate underlying metabolic mechanisms in a subpopulation of patients of the SLIM trial, where a laparoscopic proximal Roux-en-Y gastric bypass (LRYGB) with a longer biliopancreatic limb (BPL) is compared to a standard LRYGB. For this purpose, the aim is to examine differences in number of intestinal enteroendocrine cells, subpopulations of intestinal macrophages, and gene expression or DNA-methylation in tissue samples obtained by colonoscopy from the ileum and transverse colon. In addition, gut microbiota (from colon biopsy and fecal samples), meal-stimulated gut hormone profiles, glycemic control, and metabolite patterns (metabolomics; in blood, urine, stool and breath) including plasma bile acid concentrations preoperatively and 6 months post-surgery will be examined. Body composition (fat mass and lean mass) will be measured by means of BIA (bioimpedance analysis; Biacorpus).
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Long Biliopancreatic Limb LRYGB | Active comparator | Procedure: Long Biliopancreatic Limb LRYGB25 morbidly obese patients undergoing gastric bypass surgery, participating in SLIM Trial. |
| Short Biliopancreatic Limb LRYGB | Active comparator | Procedure: Short Biliopancreatic Limb LRYGB25 morbidly obese patients undergoing gastric bypass surgery, participating in SLIM Trial. |
| Control | No intervention | –15 normal weight control group without surgery. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- 2 x 25 patients with morbid obestiy (BMI of 35 kg/m2 or higher) who comply with the regulatory rules for bariatric surgery in Switzerland (SMOB guidelines) and participate in the SLIM Trial
- 15 healthy lean controls
Key exclusion criteria (23 listed)
- general contraindications to kind of surgery
- known or suspected non-compliance
- inability to follow the procedures of the study, e.g. due to language problems, psychological disorders etc. of the participant
- participation in another interventional study
- BMI > 60 kg/m2
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Long Biliopancreatic Limb LRYGBLRYGB with an 180 cm biliopancreatic limb (BPL) and an alimentary limb (AL) of 80 cm. | Procedure or surgery | Long Biliopancreatic Limb LRYGB |
| Short Biliopancreatic Limb LRYGBStandard LRYGB with a 80 cm BPL and a 180 cm long AL. | Procedure or surgery | Short Biliopancreatic Limb LRYGB |
Primary outcome
Change in glucose tolerance
Time frame: pre-OP and 6-8 months post-OP
Change in glucose tolerance as measured by plasma glucose concentrations at 120 minutes after ingestion of a standardized liquid test meal, pre-OP and 6-8 months post-OP.
35 secondary outcomes
glycemic control
Time frame: pre-OP and 6-8 months post-OP
intestinal glucose absorption rate
Time frame: pre-OP and 6-8 months post-OP
gastrointestinal peptides
Time frame: pre-OP and 6-8 months post-OP
intestinal enteroendocrine cells
Time frame: pre-OP and 6-8 months post-OP
intestinal macrophages
Time frame: pre-OP and 6-8 months post-OP
gut microbiota composition
Time frame: pre-OP and 6-8 months post-OP
bile acids
Time frame: pre-OP and 6-8 months post-OP
inflammatory profile
Time frame: pre-OP and 6-8 months post-OP
enterocyte gene expression
Time frame: pre-OP and 6-8 months post-OP
appetite-related sensations
Time frame: pre-OP and 6-8 months post-OP
body composition
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 1
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 2
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 3
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 4
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 5
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 6
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 7
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 8
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 9
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 10
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 11
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 12
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 13
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (blood) 14
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (stool) 1
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (stool) 2
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (stool) 3
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (urine) 1
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (urine) 2
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (urine) 3
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (urine) 4
Time frame: pre-OP and 6-8 months post-OP
mineral metabolism (urine) 5
Time frame: pre-OP and 6-8 months post-OP
metabolomic patterns
Time frame: pre-OP and 6-8 months post-OP
immune response
Time frame: pre-OP and 6-8 months post-OP
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Apr 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Anne Christin Meyer-Gerspach, PD Dr. phil. II Dr. habil. principal investigator
St. Clara Forschung AG / St. Claraspital AG
Bettina Wölnerhanssen, PD Dr. med. principal investigator
St. Clara Forschung AG / St. Claraspital AG
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Long Biliopancreatic Limb LRYGB and Short Biliopancreatic Limb LRYGB in people with Obesity, Morbid, run by University Hospital, Basel, Switzerland at 1 site in Switzerland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 23 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 29 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in glucose tolerance (time frame: pre-OP and 6-8 months post-OP). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Apr 2026.