Australian society is recognized for its relatively high daily intake of dietary fibre, but our citizens are still afflicted with some of the highest global incidence rates of gastrointestinal cancers, inflammatory bowel diseases (IBD), obesity, and related metabolic diseases. Furthermore, functional gastrointestinal disorders such as dyspepsia and irritable bowel syndrome are among the most common reasons for medical consultations in Australia; with commensurate social and economic burdens for both patients and Australia’s health care systems. Given there are really no cures for many of these conditions, there is a pressing need to better understand the biological drivers of their causation and recurrence, and to translate that knowledge into more effective diagnoses and treatments. In that context, the gut microbiota and its "microbiome" are now widely believed to be an extension of the host: a functional and dynamic interface of the Genotype x Environment x Lifestyle interactions that influence our health and well-being. This presentation will highlight our collaborative studies with French and Australian scientists of the gut microbiome, with specific emphasis on Crohn’s disease and the bacterium Faecalibacterium prausnitzii. In summary, our studies to date have shown: i) it is a dominant member of the gut microbiota of healthy adults; ii) two key longitudinal studies of CD patients in France and Australia suggest the low abundance and poor restoration of F. prausnitzii populations might be predictive of recurrent disease and; iii) F. prausnitzii strains produce anti-inflammatory properties and enhance intestinal barrier function. Key features within the core and accessory genomes of F. prausnitzii strains suggest a better understanding of the physiological and metabolic attributes of F. prausnitzii could translate into new opportunities to enhance its abundance in IBD patients, attenuate gut inflammation, and protect against recurrent disease. Last, the presentation will highlight the opportunities that metagenomic datasets provide for the isolation of the “most-wanted, not-yet-cultured” microbes from the gut.