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Translational research on Metabolic Surgery

Research focus

Our preclinical and clinical research focuses on the pathomechanisms of obesity and metabolic syndrome on fibrogenesis in metabolic-dysfunction associated fatty liver disease (MAFLD), and on the effects of bariatric-metabolic surgery on the interaction between intestine, liver and adipose tissue.

Bariatric-metabolic surgery leads to an efficient weight reduction and thus to a significant improvement of MAFLD. Despite the outstanding improvement or complete reversal of fatty liver and steatohepatitis, an increase in liver fibrosis has been described in up to 19% of patients following bariatric-metabolic surgery. In rare cases, even liver dysfunction was observed. The underlying cause of fibrosis progression/liver dysfunction, which occurs rarely but with detrimental consequences, is not clear.

As part of our basic scientific research, we are investigating which underlying molecular mechanisms are involved in the pathogenesis of liver fibrosis in patients with obesity and after bariatric-metabolic surgery. Aspects of molecular nutrition and immune regulation are of particular interest. These areas are investigated both in our clinical studies, in vivo (also in a rat model) and in vitro (using cell cultures). The analysis of biological materials from in vivo and in vitro experiments in combination with the examination of patient samples enables us to transfer our laboratory-generated data to humans. The continuous improvement of patient care is always at the centre of our research.

Another essential goal of our working group is the further development and improvement of surgical methods for bariatric-metabolic interventions. Thus, the randomised controlled Bilitec study is investigating the influence of anti-reflux sutures on bile reflux in patients undergoing a single-anastomosis gastric bypass (OAGB).


Gerhard Prager| © MedUni Wien/feelimage

Prof. Gerhard PRAGER, MD


Professor for Bariatric Surgery


Magdalena Mairinger | © MedUni Wien/feelimage

Magdalena MAIRINGER, MD, PhD

Christine Mölzer | © MedUni Wien/feelimage

Dr. Christine MÖLZER

Moritz Felsenreich | © MedUni Wien/feelimage



Paula Richwien | © MedUni Wien/feelimage


Predoctoral Fellow

Natalie Vock | © MedUni Wien/feelimage

Natalie VOCK, MD, BSc

Predoctoral Fellow


Accuracy of non-invasive liver stiffness measurement and steatosis quantification in patients with severe and morbid obesity M Eilenberg, P Munda, J Stift, F Langer, G Prager, M Trauner, K Staufer Hepatobiliary Surg Nutr 2021 Oct;10(5):610-622.  doi: 10.21037/hbsn-20-787.

Combined effects of PNPLA3, TM6SF2 and HSD17B13 variants on severity of biopsy-proven non-alcoholic fatty liver disease  R. Paternostro, K. Staufer, S Traussnigg , A-F Stättermayer , E Halilbasic, O Keritam, E L Meyer , Judith Stift, F Wrba , B Sipos, A Canbay , M Schlattjan , E Aigner, C Datz, F Stickel, C Schafmayer, J Hampe, S Buch, G Prager, P Munda, M Mandorfer, P Ferenci, M Trauner Hepatol Int 2021 Aug;15(4):922-933.  doi: 10.1007/s12072-021-10200-y. Epub 2021 Jun 2

Antibody-mediated targeting of cleavage-specific OPN-T cell interactions. Wanko B, Tardelli M, Jürets A, Neuhofer A, Prager G, Morser J, Leung LL, Staffler G, Zeyda M, Stulnig TM.PLoS One. 2019 Apr 5;14(4):e0214938. doi: 10.1371/journal.pone.0214938.

Significant Liver-Related Morbidity After Bariatric Surgery and Its Reversal-a Case Series. M Eilenberg, FB Langer, A Beer, M Trauner, G Prager, K Staufer. Obes Surg. 2018 Mar;28(3):812-819. doi: 10.1007/s11695-017-2925-x. 

The non-invasive serum biomarker soluble Axl accurately detects advanced liver fibrosis and cirrhosis. Staufer K, Dengler M, Huber H, Marculescu R, Stauber R, Lackner C, Dienes HP, Kivaranovic D, Schachner C, Zeitlinger M, Wulkersdorfer B, Rauch P, Prager G, Trauner M, Mikulits W.Cell Death Dis. 2017 Oct 26;8(10):e3135. doi: 10.1038/cddis.2017.554.

Adiponectin regulates aquaglyceroporin expression in hepatic stellate cells altering their functional state.Tardelli M, Moreno-Viedma V, Zeyda M, Itariu BK, Langer FB, Prager G, Stulnig TM.J Gastroenterol Hepatol. 2017 Jan;32(1):253-260. doi: 10.1111/jgh.13415.

Upregulated TNF Expression 1 Year After Bariatric Surgery Reflects a Cachexia-Like State in Subcutaneous Adipose Tissue. Jürets A, Itariu BK, Keindl M, Prager G, Langer F, Grablowitz V, Zeyda M, Stulnig TM. Obes Surg. 2017 Jun;27(6):1514-1523. doi: 10.1007/s11695-016-2477-5.

The Effect of Roux-en-Y vs. Omega-Loop Gastric Bypass on Liver, Metabolic Parameters, and Weight Loss. Kruschitz R, Luger M, Kienbacher C, Trauner M, Klammer C, Schindler K, Langer FB, Prager G, Krebs M, Ludvik B. Obes Surg. 2016 Sep;26(9):2204-2212. doi: 10.1007/11695-016-2083-6.


17012- Mayor's Medical and Scientific Fund award

Prospective, randomised, controlled study of the Omega Loop gastric bypass with and without anti-reflux sutures - a pilot study

V-940 Elise Richter Post-Doc Grant of the FWF

Gut permeability and bariatric metabolic surgery

weitere Informationen

21119 - Mayor's Medical and Scientific Fund award

Gut permeability in patients with fatty liver disease before and after bariatric metabolic surgery - a prospective cohort study

Clinical studies


Intestinal permeability in patients with non-alcoholic fatty liver disease undergoing bariatric-metabolic surgery - a prospective cohort study


Status: Active recruiting
Sponsor: Medical University of Vienna


Biliary Reflux in One Anastomosis Gastric Bypass with and without Anti-Reflux Sutures – A Randomized Controlled Trial


Status:            Active, recruiting
Sponsor:         Medical University of Vienna

Gerhard Prager | © MedUni Wien/feelimage

Univ.-Prof. Dr. Gerhard PRAGER

Professor for Bariatric Surgery

Head Metabolische und Bariatrische Chirurgie

Office 7C
Tel.: +43 (0)1 40400-56811
Tina Erber
Room 07.C1.09