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

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: Active, not recruiting
• Conditions: Obesity, Morbid
• Intervention / Treatment: Procedure: Long Biliopancreatic Limb LRYGB; Procedure: Short Biliopancreatic Limb LRYGB

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: Interventional
• Enrollment (Estimated): 65
• Phase: Not Applicable

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• 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

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

Outcome Measure	Measure Description	Time Frame
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.	pre-OP and 6-8 months post-OP

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
glycemic control	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	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	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	Differences in number and phenotype (protein expression) of intestinal enteroendocrine cells (from ileum biopsies)	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)	pre-OP and 6-8 months post-OP
gut microbiota composition	Differences in gut microbiota composition (from colon biopsy and fecal sample)	pre-OP and 6-8 months post-OP
bile acids	Differences in bile acids and metabolomic patterns (blood)	pre-OP and 6-8 months post-OP
inflammatory profile	Differences in inflammatory profile measured by hsCRP in blood	pre-OP and 6-8 months post-OP
enterocyte gene expression	Differences in enterocyte gene expression or DNA-methylation (tissue samples from ileum biopsies)	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	pre-OP and 6-8 months post-OP
body composition	Body composition (measured by Bio Impedance Analysis (BIA))	pre-OP and 6-8 months post-OP
mineral metabolism (blood) 1	Differences in mineral metabolism parameter (creatinine) in blood samples.	pre-OP and 6-8 months post-OP
mineral metabolism (blood) 2	Differences in mineral metabolism parameter (phosphate) in blood samples.	pre-OP and 6-8 months post-OP
mineral metabolism (blood) 3	Differences in mineral metabolism parameter (calcium) in blood samples.	pre-OP and 6-8 months post-OP
mineral metabolism (blood) 4	Differences in mineral metabolism parameter (magnesium) in blood samples.	pre-OP and 6-8 months post-OP
mineral metabolism (blood) 5	Differences in mineral metabolism parameter (parathyroid hormone) in blood samples.	pre-OP and 6-8 months post-OP
mineral metabolism (blood) 6	Differences in mineral metabolism parameter (calcidiol) in blood samples.	pre-OP and 6-8 months post-OP
mineral metabolism (blood) 7	Differences in mineral metabolism parameter (calcitriol) in blood samples.	pre-OP and 6-8 months post-OP
mineral metabolism (blood) 8	Differences in mineral metabolism parameter (FGF23) in blood samples.	pre-OP and 6-8 months post-OP
mineral metabolism (blood) 9	Differences in mineral metabolism parameter (desoxypyridinoline) in blood samples.	pre-OP and 6-8 months post-OP
mineral metabolism (blood) 10	Differences in mineral metabolism parameter (bone alkaline phosphatase (bALP)) in blood samples.	pre-OP and 6-8 months post-OP
mineral metabolism (blood) 11	Differences in mineral metabolism parameter (osteocalcin) in blood samples.	pre-OP and 6-8 months post-OP
mineral metabolism (blood) 12	Differences in mineral metabolism parameter (sclerostin) in blood samples.	pre-OP and 6-8 months post-OP
mineral metabolism (blood) 13	Differences in mineral metabolism parameter (P1NP) in blood samples.	pre-OP and 6-8 months post-OP
mineral metabolism (blood) 14	Differences in mineral metabolism parameter (CTX) in blood samples.	pre-OP and 6-8 months post-OP
mineral metabolism (stool) 1	Differences in mineral metabolism parameter (phosphate) in feces samples.	pre-OP and 6-8 months post-OP
mineral metabolism (stool) 2	Differences in mineral metabolism parameter (calcium) in feces samples.	pre-OP and 6-8 months post-OP
mineral metabolism (stool) 3	Differences in mineral metabolism parameter (magnesium) in feces samples.	pre-OP and 6-8 months post-OP
mineral metabolism (urine) 1	Differences in mineral metabolism parameter (creatinine) in urine samples.	pre-OP and 6-8 months post-OP
mineral metabolism (urine) 2	Differences in mineral metabolism parameter (phosphate) in urine samples.	pre-OP and 6-8 months post-OP
mineral metabolism (urine) 3	Differences in mineral metabolism parameter (calcium) in urine samples.	pre-OP and 6-8 months post-OP
mineral metabolism (urine) 4	Differences in mineral metabolism parameter (magnesium) in urine samples.	pre-OP and 6-8 months post-OP
mineral metabolism (urine) 5	Differences in mineral metabolism parameter (desoxypyridinoline) in urine samples.	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.	pre-OP and 6-8 months post-OP
immune response	Differences in immune response biomarkers in blood measured by a cytokine screening assay	pre-OP and 6-8 months post-OP

Collaborators and Investigators

• Sponsor: University Hospital, Basel, Switzerland
• Investigators: 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

Study Major Dates

• Study Start (Actual): August 1, 2022
• Primary Completion (Estimated): October 1, 2026
• Study Completion (Estimated): October 1, 2026

Study Registration Dates

• First Submitted: March 21, 2022
• First Submitted That Met QC Criteria: July 20, 2022
• First Posted (Actual): July 22, 2022

Study Record Updates

• Last Update Posted (Actual): April 29, 2026
• Last Update Submitted That Met QC Criteria: April 28, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Overweight; Obesity; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity, Morbid
• Other Study ID 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