Investigating the metabolic effects of gastric bypass surgery

The focus of the Metabolic Research Unit at WSU Blacktown Clinical School is to establish a network of collaborative projects in Western Sydney Local Health District in endocrine, metabolic and cancer research, investigating hormonal control of metabolism, body composition and cancer development. The Metabolic Research Unit is equipped to perform a wide range of body composition, energy expenditure, substrate utilization, physical capacity, muscle strength, and balance assessments. State-of-the-art techniques are implemented using stable isotopes to investigate whole body protein metabolism, urea turnover, and liver fat export. This laboratory is the only one in Australia who can perform such complex stable isotope studies in humans. Another large initiative at Blacktown Clinical School is establishment of bariatric surgery and lifestyle management service at Blacktown Hospital with a multidisciplinary research team. This program will result in a development of metabolic research-oriented network, enabling also to support large variety of student research projects.

New program of lifestyle and surgical therapy for management of obesity and obesity-related diseases at Blacktown Hospital has been established. The overall aim of this WSU research program is to investigate what factors determine weight gain and how diet or gastric surgery improve metabolism, and physical and mental health.

Obesity affects approximately half a billion adults worldwide, with profound pathological effects, such as hypertension, dyslipidaemia, high prevalence of Non-Alcoholic Fatty Liver Disease (NAFLD), diabetes, cardiovascular complications, stroke, osteoarthritis, and some cancers. Bariatric surgery is now considered the most effective modality for sustainable weight loss and for curing co-morbidities. Recent studies provide evidence of a rapid improvement in diabetes control after bariatric surgery before major changes in body composition have occurred.
Specific aim of this project is to establish the mechanism for rapid beneficial effect of bariatric surgery on diabetes and liver fat improvement. Hypothesis is that in patients after gastric bypass surgery, exaggerated increase in postprandial bile acids, incretins and certain gut hormones, and changes in microbiome improve glucose metabolism before changes in body composition have occurred.

Patients undergoing gastric bypass or sleeve surgery will be compared to patients who will undergo weight loss program through diet alone. We will investigate the postprandial changes in circulating factors, gut hormones and enzymes, and changes in glucose metabolism after gastric surgery. Stool for microbiome analysis will be collected at each visit to determine species composition and microbial metabolism. Liver fat content and body composition will be assessed.

We expect that patients with gastric bypass surgery will have rapid post-prandial increase in circulating gut-derived factors that will be paralleled by rapid improvements in insulin sensitivity. These early changes will determine later changes in body composition and diabetes control. Understanding bile acid metabolism after bariatric surgery, and the mechanism how gut-derived factors and changes in microbiome regulate glucose metabolism will enable future therapy development to improve diabetes control. This study will provide array of circulating markers and microbiome that could be used to measure in patients undergoing weight loss programs, in particular gastric surgery, to predict the rate of weight loss and the extent of benefit in curing co-morbidities, such as NAFLD and diabetes.

An opportunity has arisen for a 3-year PhD studentship within the School of Medicine, WSU at Blacktown Clinical School, Blacktown NSW. The title of the project is “Novel mechanisms for rapid improvement in diabetes and liver fat after bariatric surgery “. This will be a clinical research-oriented PhD with some basic research component.

Applicants must be Australian citizens or permanent residents, and should have experience in patient care and basic understanding of research principles. Laboratory experience is desirable. The PhD must be undertaken on a full-time basis. Applicants must already have been awarded a first class Honours degree or hold equivalent qualifications and relevant research experience in an appropriate sector. Applicants should be able to demonstrate strong research and analytical skills.

Applicants should submit their CV and a covering letter, including full contact details of two referees, to Dr Vita Birzniece at