Dr Christina Adler
C24 - Westmead Hospital
Bachelor of Science (Major in Anatomy and Immunology), The University of Sydney, 2005. First Class Honours and the University Medal (Anatomy), The University of Sydney, 2006. Thesis title: ‘Sexual dimorphism in the morphometric crown traits in the deciduous dentition of a Caucasoid Australian sample’. Supervisor: Dr Denise Donlon. Doctor of Philosophy, The University of Adelaide, awarded January 2012. Thesis title: ''Ancient DNA studies of human evolution''. Supervisors: Dr Wolfgang Haak, Professor Alan Cooper and Dr Denise Donlon.
My current research focuses on several important problems in oral health, including determining how the oral ecosystem has evolved from a prehistoric state where oral diseases were rare (e.g. before the development of agriculture) to a state of chronic infection and disease. To determine this I am using oral microbial DNA from prehistoric and modern dental tissues and applying metagenomic techniques to reveal directly the impact of past and current dietary associated environmental changes on the bacterial composition of the oral ecosystem. In addition to the impact of dietary induced environmental change, I am investigating how an individual’s genetic makeup together with their environment drives variation in the composition and functional capacity of the oral microbiota to produce disease.
I currently have three major projects (outlined below) which together aim to determine what factors are causing the oral microbial ecosystem to become increaseingly diseased. There are Honors and PhD projects avaliable for the research programs detailed below. Please contact me if you are interested in any of the projects or other related work.
1. The impact of past dietary changes on the oral ecosystem – Ancient dental calculus
The importance of microbes in human health is being increasingly recognized, yet the impacts of past changes in human diet on commensal microbiota remain largely unknown. Arguably, two of the greatest dietary shifts in human evolution involved the adoption of carbohydrate-rich Neolithic (farming) diets (beginning ~10,000 yBP), and the morerecent advent of industrially processed flour and sugar (~1800 AD). This project utilises ancient oral microbial DNA recovered from dental calculus to reveal how the oral microbial ecosystem has altered as humans have undergone these major dietary transitions. I developed this technique during my PhD (awarded January 2012) with colleagues at The Australian Centre for Ancient DNA, The University of Adelaide. This information is being used to improve our current understanding of what constitutes a healthy mouth in terms of bacterial makeup. Future research will focus on determine thetiming, mechanism of acquisition and assembly of known virulence genes from human pathogens in real time. This research builds on my background in human population genetics and dental anthropology.
Collaborators: Professor Alan Cooper (The University of Adelaide) and Professor Keith Dobney (The University of Aberdeen).
2. The impact of current dietary changes on the oral ecosystem – nutritional study
My research into past dietary changes has indicated that the variation in macronutrient content associated with the introduction of farming, namely a drop in protein and an increase in carbohydrates, influenced the composition of the oral microbiota and hence oral health. I am currently testing this hypothesis by genetically analyzing the oral microbiota of mice which have been subjected to 30 different diets, each with varying levels protein, carbohydrate and lipid intake. This research is part of a larger study being undertaken by the Behaviour and Physiology Research Group led by Professor Stephen Simpson at the University of Sydney (School of Biological Sciences). The nutritional study is investigating the links between caloric and macronutrient intake on obesity, aging and immunity. My research into the changes in oral microbiota with diet will also be used to investigate what role the oral ecosystem may play in systemic disorders.
Collaborators: Professor Stephen Simpson (The University of Sydney) and Professor Alan Cooper (The University of Adelaide).
3. The impact of an individual’s genetic makeup and their environment on the developing oral microbiota in childhood – Twin study
Dental decay (or caries) is the most common chronic disease affecting Australian children, and as such, inflicts a huge economic burden on society. The current consensus, is that caries is caused by a microbial shift from homeostasis to an aciduric state due to the lowering of pH brought on by sugar consumption. This hypothesis does not consider the role of host genetic factors in influencing the development of caries, an effect which we have demonstrated through our study of oral microbiota in a cohort of Australian children (300 monozygotic and 300 dizygotic twin pairs). These twins have been followed from 3 months to 5 years of age by the Craniofacial Biology Unit at The University of Adelaide. We aim to extend our understanding of caries in childhood by revealing how genetic and environmental factors drive variation in the composition of the oral microbiota, leading to either dental decay or oral health. We will perform in-depth genetic analysis on the dental plaque samples from the twin cohort described above to test the hypothesis: Genetic factors significantly influence variation in the composition of the oral microbiota associated with caries, and therefore explain variation in oral health. At a population level, we will use our findings to direct treatment approaches by discovering new anti-caries taxa in the oral microbiota. At a practitioner level, our study will enable screening methods to be established which effectively identify high caries risk individuals.
Collaborators: Professor Grant Townsend, Dr Toby Hughes and Ms Abbe Harris (The University of Adelaide).
Successful Grants as Chief Investigator
Wellcome Trust (WT092799MA), 2010, $28,506, Project Title: Proof of concept research project, Archaeological Dental Calculus: A novel source of genetic information the evolution of oral bacteria and pathogens
The Sir Mark Mitchell Research Foundation(ID 75105072), 2009-2010, $4,000, Project Title: Reconstruction of lifestyle in prehistoric human populations from dental calculus.
Successful Grants as a Collaborator
Australian Research Council, Discovery Grant (DP110105038)2011-2014, $380,000, Project Title:A powerful new genetic view of the recent evolutionary history of humans and their diseases.