title: Effects of surgical and dietary weight loss therapy for obesity on gut microbiota composition and nutrient absorption.
abstract: Evidence suggests a correlation between the gut microbiota composition and weight loss caused by caloric restriction. Laparoscopic sleeve gastrectomy (LSG), a surgical intervention for obesity, is classified as predominantly restrictive procedure. In this study we investigated functional weight loss mechanisms with regard to gut microbial changes and energy harvest induced by LSG and a very low calorie diet in ten obese subjects (n = 5 per group) demonstrating identical weight loss during a follow-up period of six months. For gut microbiome analysis next generation sequencing was performed and faeces were analyzed for targeted metabolomics. The energy-reabsorbing potential of the gut microbiota decreased following LSG, indicated by the Bacteroidetes/Firmicutes ratio, but increased during diet. Changes in butyrate-producing bacterial species were responsible for the Firmicutes changes in both groups. No alteration of faecal butyrate was observed, but the microbial capacity for butyrate fermentation decreased following LSG and increased following dietetic intervention. LSG resulted in enhanced faecal excretion of nonesterified fatty acids and bile acids. LSG, but not dietetic restriction, improved the obesity-associated gut microbiota composition towards a lean microbiome phenotype. Moreover, LSG increased malabsorption due to loss in energy-rich faecal substrates and impairment of bile acid circulation. This trial is registered with ClinicalTrials.gov NCT01344525.
authors.affiliation: Department of Nutritional Medicine, University of Hohenheim, Fruwirthstraße 12, 70599 Stuttgart, Germany.
authors.forename: Antje
authors.initials: A
authors.lastname: Damms-Machado
authors.affiliation: Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551.
authors.forename: Suparna
authors.identifier: 0000-0002-9378-1496
authors.initials: S
authors.lastname: Mitra
authors.affiliation: Department of Nutritional Medicine, University of Hohenheim, Fruwirthstraße 12, 70599 Stuttgart, Germany ; Department of General, Visceral and Transplant Surgery, University of Tübingen, 72076 Tübingen, Germany.
authors.forename: Asja E
authors.initials: AE
authors.lastname: Schollenberger
authors.affiliation: Department of General and Visceral Surgery, Chirurgische Klinik München-Bogenhausen, 81679 Munich, Germany.
authors.forename: Klaus Michael
authors.initials: KM
authors.lastname: Kramer
authors.affiliation: Department of General, Visceral and Transplant Surgery, University of Tübingen, 72076 Tübingen, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Meile
authors.affiliation: Department of General, Visceral and Transplant Surgery, University of Tübingen, 72076 Tübingen, Germany.
authors.forename: Alfred
authors.initials: A
authors.lastname: Königsrainer
authors.affiliation: Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551 ; Center for Bioinformatics, University of Tübingen, 72076 Tübingen, Germany.
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Huson
authors.affiliation: Department of Nutritional Medicine, University of Hohenheim, Fruwirthstraße 12, 70599 Stuttgart, Germany.
authors.forename: Stephan C
authors.initials: SC
authors.lastname: Bischoff
mesh_terms: D001419:Bacteria / Q000302:isolation & purification*; D031204:Caloric Restriction; D003131:Combined Modality Therapy; D005260:Female; D005743:Gastrectomy; D000069196:Gastrointestinal Microbiome; D005858:Germany; D006801:Humans; D007408:Intestinal Absorption; D008875:Middle Aged; D009765:Obesity / Q000382:microbiology* / Q000503:physiopathology / Q000628:therapy*; D016896:Treatment Outcome