Digestive Health

Research Team

Public Summary

Principal Investigator: Professor Nicole Roy, AgResearch

Collaborating Organisations: Malaghan Institute, University of Otago, Plant and Food Research

In NZ’s large and growing food export markets in Asia we know that digestive health is a common and rising topic of concern. Healthy digestion is critical to physical health, and mental health and well-being. Approximately 30% of the population has at least one of the functional gastrointestinal disorders where “everything looks normal” and there is no detectable disease, but there are abnormal digestive processes such as altered transit and hypersensitivity. The mechanisms underpinning these health parameters are poorly defined.

Our research programme focuses on NZ food and beverage products for improving gastrointestinal function and comfort. We seek to understand the linkages between diet, gastrointestinal symptoms and disorders, metabolism, physiology and microbial populations (the microbiome) to better predict food-health gastrointestinal relationships. This will enable the NZ food and beverage industry to predict the gastrointestinal health benefits of foods and ingredients and generate validated scientific evidence of these health benefits.

Our understanding of the linkages between diet, gastrointestinal symptoms, metabolism, physiology and the microbiome has been enabled by the establishment of a patient cohort, named COMFORT, and a database of information relating to the cohort. This has involved the development of a world-first validated questionnaire, the Food and Symptom Times diary which addresses a knowledge gap by enabling the food consumed on a given day to be linked with gastrointestinal symptoms. Other validated questionnaires addressing gastrointestinal symptoms, anxiety and depression symptoms and quality of life were used to cluster the participants recruited into the COMFORT cohort: healthy controls and those with constipation or diarrhoea, including individuals with irritable bowel syndrome. International collaborations have enabled world-leading methods to be used for the analysis of a comprehensive suite of metabolites present in plasma, urine and breath samples obtained from the participants.

Our analyses have highlighted differences between COMFORT participants and healthy symptom-free control participants. We have seen perturbations in amino acid and lipid metabolism that are known to be associated with gastrointestinal dysfunction. Analysis of the microbiome genetic information in faecal samples has shown potential microbial mechanisms that distinguish between participants with functional gastrointestinal disorders and healthy participants. These results provide an important first step in understanding how the gastrointestinal microbiome impacts human health when gastrointestinal function is suboptimal. Our approach has enabled greater knowledge on microbiome composition and function than other studies, and we now have strong evidence that we can cluster these disorders based on metabolic and microbial biomarkers.

The research team is multidisciplinary, comprising leading NZ researchers who collaborate internationally and present their research to the global research community. International world-leading researchers in the gastrointestinal field recognise the Healthy Digestion programme as unique in its approach and scale, having the potential to generate significant health and industry outcomes.

The research team includes a Māori researcher affiliated to Ngāti Porou and Ngāti Raukawa, who is progressing Māori science leadership opportunities and capability in the integration of high-dimensional biological data with clinical data. We are committed to strengthening Māori researcher capacity and capability within our programme as we progress our research.

The Healthy Digestion programme works closely with the NZ food and beverage industry, including Māori agribusinesses, to ensure our research is relevant for industry. This includes work with NZ industry partners to validate our approach and test food concepts. We will continue to assist Māori and non-Māori food and beverage entities, in developing and testing novel foods for improved gastrointestinal health outcomes. The programme supports the mission of the High-Value Nutrition Challenge to generate knowledge and capability that the NZ food and beverage industry can utilise to develop high-value foods with validated health outcomes and thus increase export revenues.

Publications

2019

Fraser, K., W. Young, W. McNabb, R. Gearry & N. Roy. (2019). Lipid and metabolite profiles in human plasma and associations with the microbiome and functional gastrointestinal disorders (P20-033-19). Current Developments in Nutrition. 3(1). https://doi.org/10.1093/cdn/nzz040.P20-033-19

James, C., K. Fraser, W. Young, W. McNabb, R. Gearry & N. Roy. (2019). Understanding how metabolites link diet, host, and microbiota in a dysfunctional gut model is important to establishing a system-wide understanding of gut function (P20-035-19). Current Developments in Nutrition. 3(1).  https://doi.org/10.1093/cdn/nzz040.P20-035-19

Kortlever TL, Ten Bokkel Huinink S, Offereins M, Hebblethwaite C, O’Brien L, Leeper J, Mulder CJJ, Barrett JS, Gearry RB. (2019). Low-FODMAP Diet Is Associated With Improved Quality of Life in IBS Patients-A Prospective Observational Study. Nutr Clin Pract. https://doi.org/10.1002/ncp.10233

Mullaney JA, Stephens JE, Geeling BE & Hamilton-Williams EE. (2019). Early-life exposure to gut microbiota from disease-protected mice does not impact disease outcome in type 1 diabetes susceptible NOD mice. Immunology and Cell Biology.  https://doi.org/10.1111/imcb.12201

Young, W., C. Carco, J. Mullaney, P. Maclean, P. Cotter, K. Fraser, W. McNabb, R. Gearry & N. Roy. (2019). The microbiome in functional gastrointestinal disorders is characterized by bacteria and genes involved in carbohydrate and bile acid metabolism (OR23-01-19). Current Developments in Nutrition. 3(1).  https://doi.org/10.1093/cdn/nzz040.OR23-01-19

2018

Aidoud, N., Delplanque, B., Baudry, C., Garcia, C., Moyon, A., Balasse, L., Guillet, B., Antona, C., Darmaun, D., Fraser, K., Ndiaye, S., Leruyet, P. & Martin, J.C. (2018). A combination of lipidomics, MS imaging, and PET scan imaging reveals differences in cerebral activity in rat pups according to the lipid quality of infant formulas. FASEB Journal. 32(9). https://doi.org/10.1096/fj.201800034R

Gavin, PG., Mullaney, JA., Loo, D., Lê Cao, K-A., Gottlieb, PA, Hill, MM., Zipris, D. & Hamilton-Williams, EE. (2018). Intestinal metaproteomics reveals host-microbiota interactions in subjects at risk for type 1 diabetes.  Diabetes Care. 41(10): 2178-2186. https://doi.org/10.2337/dc18-0777. 

Laing, B., Barnett, MPG., Marlow, G., Nasef, NA. & Ferguson, LR. (2018). An update on the role of gut microbiota in chronic inflammatory diseases, and potential therapeutic targets. Expert Review of Gastroenterology and Hepatology. 12(10): 969-983. https://doi.org/10.1080/17474124.2018.1505497.

McCann, M.J., Rotjanapun, K., Hesketh, J.E. & Roy, N.C. (2018). Expression profiling indicating low selenium-sensitive microRNA levels linked to cell cycle and cell stress response pathways in the CaCo-2 cell line. British Journal of Nutrition. 117(9):1212-1221. https://doi.org/10.1017/S0007114517001143

Mullaney, J.A., Stephens, J.E., Costello, M.E., Fong, C., Geeling, B.E.; Gavin, P.G., Wright, C.M., Spector, T.D., Brown, M.A. & Hamilton-Williams, E.E. (2018). Type 1 diabetes susceptibility alleles are associated with distinct alterations in the gut microbiota. Microbiome. 6(1):51. https://doi.org/10.1186/s40168-018-0438-z

Riedle, S., Pele, L.C., Otter, D.E., Hewitt, R.E., Singh, H., Roy, N.C. & Powell, J.J. (2018). Pro-inflammatory adjuvant properties of pigment-grade titanium dioxide are augmented by an ‘at-risk’-genotype that potentiates interleukin 1β processing. Particle and Fibre Toxicology. 14(1):51.  https://doi.org/10.1186/s12989-017-0232-2