Colorectal cancer (CRC) is a major health problem in New Zealand and classifying CRC into subtypes could refine treatment and reduce disease-related mortality. We will stratify our cohort of NZ CRC tumours into molecular subtypes using gene-expression profiles, and use clinical and follow-up data to investigate the associations of the molecular subtypes with outcome and response to therapy. We will also investigate the contribution of changes in the gut microbiome to the development of CRC using metagenomic analysis, and analyse association patterns between bacterial species found at the tumour sites and clinical, histological and outcome data. Finally, we will amalgamate the two parts of the project to reveal particular species of bacteria or types of virulence factors involved the development of a particular CRC subtype. This would represent an important step in translating data on microbiome sequencing to clinical contexts and facilitate the development of non-invasive clinical tests for CRC.