Different Limb Lengths in Gastric Bypass Surgery (SLIM) - Part 3: Metabolism and Inflammation (SLIM - Part 3)

April 28, 2026 updated by: University Hospital, Basel, Switzerland

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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 Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
65

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Switzerland
      • Basel, Switzerland, 4002
        • St Clara Research Ltd, St Claraspital Basel

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • 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

Exclusion Criteria:

  • 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
  • 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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Long Biliopancreatic Limb LRYGB
25 morbidly obese patients undergoing gastric bypass surgery, participating in SLIM Trial.
Procedure: Long Biliopancreatic Limb LRYGB
LRYGB with an 180 cm biliopancreatic limb (BPL) and an alimentary limb (AL) of 80 cm.
Active Comparator: Short Biliopancreatic Limb LRYGB
25 morbidly obese patients undergoing gastric bypass surgery, participating in SLIM Trial.
Procedure: Short Biliopancreatic Limb LRYGB
Standard LRYGB with a 80 cm BPL and a 180 cm long AL.
No Intervention: Control
15 normal weight control group without surgery.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
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.
pre-OP and 6-8 months post-OP

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
glycemic control
Time Frame: pre-OP and 6-8 months post-OP
Change in glucose variability measured by continuous glucose measurement over 1 week, pre-OP and 6-8 months post-OP.
pre-OP and 6-8 months post-OP
intestinal glucose absorption rate
Time Frame: pre-OP and 6-8 months post-OP
Differences in intestinal glucose absorption rate after ingestion of a standardized liquid test meal measured by 3-OMG
pre-OP and 6-8 months post-OP
gastrointestinal peptides
Time Frame: pre-OP and 6-8 months post-OP
Differences in the release of gastrointestinal peptides after ingestion of a standardized liquid test meal
pre-OP and 6-8 months post-OP
intestinal enteroendocrine cells
Time Frame: pre-OP and 6-8 months post-OP
Differences in number and phenotype (protein expression) of intestinal enteroendocrine cells (from ileum biopsies)
pre-OP and 6-8 months post-OP
intestinal macrophages
Time Frame: pre-OP and 6-8 months post-OP
Differences in the number and phenotype (gene expression, methylation) of intestinal macrophages and subpopulations (from colon biopsies)
pre-OP and 6-8 months post-OP
gut microbiota composition
Time Frame: pre-OP and 6-8 months post-OP
Differences in gut microbiota composition (from colon biopsy and fecal sample)
pre-OP and 6-8 months post-OP
bile acids
Time Frame: pre-OP and 6-8 months post-OP
Differences in bile acids and metabolomic patterns (blood)
pre-OP and 6-8 months post-OP
inflammatory profile
Time Frame: pre-OP and 6-8 months post-OP
Differences in inflammatory profile measured by hsCRP in blood
pre-OP and 6-8 months post-OP
enterocyte gene expression
Time Frame: pre-OP and 6-8 months post-OP
Differences in enterocyte gene expression or DNA-methylation (tissue samples from ileum biopsies)
pre-OP and 6-8 months post-OP
appetite-related sensations
Time Frame: pre-OP and 6-8 months post-OP
Differences in subjective appetite-related sensations (feelings of hunger, prospective food consumption, satiation and fullness) after liquid test meal, assessed with Visual Analog Scales
pre-OP and 6-8 months post-OP
body composition
Time Frame: pre-OP and 6-8 months post-OP
Body composition (measured by Bio Impedance Analysis (BIA))
pre-OP and 6-8 months post-OP
mineral metabolism (blood) 1
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (creatinine) in blood samples.
pre-OP and 6-8 months post-OP
mineral metabolism (blood) 2
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (phosphate) in blood samples.
pre-OP and 6-8 months post-OP
mineral metabolism (blood) 3
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (calcium) in blood samples.
pre-OP and 6-8 months post-OP
mineral metabolism (blood) 4
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (magnesium) in blood samples.
pre-OP and 6-8 months post-OP
mineral metabolism (blood) 5
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (parathyroid hormone) in blood samples.
pre-OP and 6-8 months post-OP
mineral metabolism (blood) 6
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (calcidiol) in blood samples.
pre-OP and 6-8 months post-OP
mineral metabolism (blood) 7
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (calcitriol) in blood samples.
pre-OP and 6-8 months post-OP
mineral metabolism (blood) 8
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (FGF23) in blood samples.
pre-OP and 6-8 months post-OP
mineral metabolism (blood) 9
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (desoxypyridinoline) in blood samples.
pre-OP and 6-8 months post-OP
mineral metabolism (blood) 10
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (bone alkaline phosphatase (bALP)) in blood samples.
pre-OP and 6-8 months post-OP
mineral metabolism (blood) 11
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (osteocalcin) in blood samples.
pre-OP and 6-8 months post-OP
mineral metabolism (blood) 12
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (sclerostin) in blood samples.
pre-OP and 6-8 months post-OP
mineral metabolism (blood) 13
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (P1NP) in blood samples.
pre-OP and 6-8 months post-OP
mineral metabolism (blood) 14
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (CTX) in blood samples.
pre-OP and 6-8 months post-OP
mineral metabolism (stool) 1
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (phosphate) in feces samples.
pre-OP and 6-8 months post-OP
mineral metabolism (stool) 2
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (calcium) in feces samples.
pre-OP and 6-8 months post-OP
mineral metabolism (stool) 3
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (magnesium) in feces samples.
pre-OP and 6-8 months post-OP
mineral metabolism (urine) 1
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (creatinine) in urine samples.
pre-OP and 6-8 months post-OP
mineral metabolism (urine) 2
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (phosphate) in urine samples.
pre-OP and 6-8 months post-OP
mineral metabolism (urine) 3
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (calcium) in urine samples.
pre-OP and 6-8 months post-OP
mineral metabolism (urine) 4
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (magnesium) in urine samples.
pre-OP and 6-8 months post-OP
mineral metabolism (urine) 5
Time Frame: pre-OP and 6-8 months post-OP
Differences in mineral metabolism parameter (desoxypyridinoline) in urine samples.
pre-OP and 6-8 months post-OP
metabolomic patterns
Time Frame: pre-OP and 6-8 months post-OP
Differences in metabolomic patterns assed in blood sample, urine sample, stool sample and exhaled breath.
pre-OP and 6-8 months post-OP
immune response
Time Frame: pre-OP and 6-8 months post-OP
Differences in immune response biomarkers in blood measured by a cytokine screening assay
pre-OP and 6-8 months post-OP

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University Hospital, Basel, Switzerland

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Anne Christin Meyer-Gerspach, PD Dr. phil. II Dr. habil., St. Clara Forschung AG / St. Claraspital AG
  • Principal Investigator: Bettina Wölnerhanssen, PD Dr. med., St. Clara Forschung AG / St. Claraspital AG

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 1, 2022

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
October 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
October 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 21, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 20, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 22, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 29, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 28, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • SLIM - Part 3

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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