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Improving digestive health by combining clinical and basic research

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We bring an interdisciplinary approach to improving digestive health by incorporating the strengths of many diverse scientific perspectives and methods including diet and nutrition, understanding bacterial action, underlying biology, inflammation, and infection.

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Volunteers wanted: Participate in our digestive health research studies

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If you are interested in postgraduate research with our group, contact us by:


Bacteria in the pathogenesis of gastrointestinal disease

The gastrointestinal tract is inhabited by a multitude of microorganisms, the so-called microbiota. The microbiota is established during birth and is involved in many physiological processes such as digestion and immune system function. The microbiota changes over time, and not all microorganisms are commensal or non-pathogenic; in some cases, they can cause inflammation and disease.

Key research interests:

  • Epithelial permeability, inflammation, and DNA damage caused by Gram-negative bacteria membrane vesicles
  • Influence of diet on bacterial phenotype and host response

Crohn's disease and Ulcerative Colitis

Both diseases are chronic, severe inflammatory diseases. In ulcerative colitis, ulcers form in the lining of the colon and rectum. In Crohn's disease, the inflammation can involve the complete digestive tract and deeper layers. Common symptoms are diarrhea and bleeding, abdominal pain and weight loss. Both diseases can be life-threatening.

Key research interests:

  • Host-pathogen interactions in the gut (and how these relate to chronic gut diseases)
  • Intestinal inflammatory biomarkers
  • Nutrition and dietary management of inflammatory bowel diseases

Functional gastrointestinal disorders

Functional gastrointestinal disorders (FGID) are common and chronic conditions of the gastrointestinal system without obvious signs of inflammation. While they are not life threatening, they can have a large impact on wellbeing. Functional gastrointestinal disorders are complex, with no clear cause. The most common disorders are functional dyspepsia, functional constipation, and Irritable Bowel Syndrome (IBS).

Key research interests:

  • Nutritional treatment of constipation symptoms
  • Systems biology investigation of functional constipation and constipation-predominant IBS
  • Prevalence of diarrhoea-predominant FGID and dietary management

Hepatitis C and autoimmune liver diseases

Hepatitis C is a virus causing liver inflammation. It is spread through blood. If untreated, it can lead to cirrhosis, liver failure, and liver cancer. Hepatitis C can be successfully treated with antiviral medication.

There are three main classes of autoimmune liver diseases:

  • Primary sclerosing cholangitis – progressive disease that scars the bile ducts
  • Primary biliary cholangitis – the progressive destruction of the small bile ducts
  • Autoimmune hepatitis – the inflammation of liver cells caused by the body's immune system

Study participants

Currently, we are not recruiting for clinical trials.

Our people

Principal Investigators

Professor Richard Gearry

Richard Gearry image 2021 GUTS

Richard is Professor at University of Otago Christchurch and Consultant Gastroenterologist at Christchurch Hospital. His research interests include Luminal Gastroenterology, Inflammatory Bowel Disease, Coeliac Disease, Irritable Bowel Syndrome and Colorectal Cancer.

He is also the Medical Director, New Zealand Nutrition Foundation, and the Medical Advisor, Crohn's and Colitis New Zealand.


Professor Andrew Day

Andrew Day image Professor Day is a paediatric gastroenterologist. His research interests include Inflammatory Bowel disease, Crohn's disease, and Coeliac disease, with projects focusing upon host-pathogen interactions in the gut (and how these relate to chronic gut diseases), intestinal inflammatory biomarkers, and nutritional aspects of gut diseases.


Clinical Professor Catherine Stedman

Catherine Stedman image 2021 GUTSClinical Professor Stedman's field of research is liver disease and pharmacology, focusing on hepatitis C and autoimmune liver diseases. Her published papers in hepatitis C epidemiology have influenced global understanding of chronic hepatitis C epidemiology including government and Ministry of Health understanding and approach to hepatitis C treatment strategies.


Associate Professor Jacqui Keenan

Jacqui Keenan imageAssociate Professor Keenan's research is centred on the role of bacteria in the pathogenesis of gastrointestinal disease. She is particularly interested in the ability of outer membrane vesicles shed from the surface of Gram-negative bacteria to induce epithelial permeability, inflammation, and DNA damage. Another interest is the influence of diet on bacterial phenotype and host response.


Research Fellows

Dr Catherine Wall

Catherine Wall image 2021 GUTSCatherine is a clinical and research dietitian. Her broad area of research interest is diet and nutrition in gastrointestinal diseases and disorders. She is particularly interested in nutrition and dietary treatments for Crohn's disease and ulcerative colitis.


Dr Simone Bayer

Simone Bayer image 2021 GUTSSimone is a laboratory-trained scientist with a background in nutrition science and expertise in clinical research. Her current focus is on functional gastrointestinal diseases, specifically irritable bowel syndrome, and on the interaction between microbiota and the immune system in the gastrointestinal system.


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