Role of the microbiome in pre-diabetes, type 2 diabetes and gut health

Currently researched by Akarsh Mathrani


The human gut contains an extraordinary amount of bacteria and other microorganisms, with these diverse microbes collectively carrying 150 times more genes than the genome of their humble human host.  Unsurprisingly, the gut microbiome has a huge impact on human health and wellbeing, affecting not only the health of our guts but even our brains and other parts of our bodies.  One area in which the gut microbiome appears to play a role is in metabolic disorders such as obesity and type 2 diabetes.  Exactly what this role is remains to be clarified, and there is much research on this topic being undertaken globally.


Type 2 diabetes (T2D) is a massive human health problem, affecting hundreds of millions of people globally.  Those identified as being at high risk of developing T2D (i.e. pre-diabetic individuals) are even greater in number, with more than one-quarter of NZ’s population having either pre-diabetes or full-blown T2D.  In close collaboration with Sally Poppitt and Marta Silvestre at the University of Auckland’s Human Nutrition Unit (HNU), we are involved in several projects to investigate the gut microbiota in humans with pre-diabetes and/or T2D.  The HNU is New Zealand’s only residential nutrition facility, and offers an invaluable resource for carefully regulated studies of this kind.  Complementing our T2D work on humans is the PhD research of Akarsh Mathrani, which examines the faecal microbiome in two transgenic mouse models of diabetes/obesity.  Our mouse work is performed in collaboration with University of Auckland researchers Garth Cooper (joint appointment with University of Manchester) and Jackie Aitken, who developed the mouse models.  This work has been made possible via generous funding from the Maurice Wilkins Centre for Molecular Biodiscovery, a NZ Centre of Research Excellence.


Another area under recent investigation was the effect of a kiwifruit extract on the gut microbiome.  Whole kiwifruit is known to improve gut health, but whether extracts (which may be more convenient to the consumer) elicit the same effects is unclear.  This work, conducted by MSc student Jonathan (Yao-Chin) Liu, was based on a recent clinical trial which sought to determine the influence of kiwifruit extracts on constipation.


Our recent publications related to the human gut microbiome include: Kia et al., 2016; Taylor, 2017; Tannock & Taylor, 2017.