Impact of Diet on Human Colonic Microbiota and Gut Metabolism - Harry Flint (Rowett Institute, Aberdeen)

Sequence analysis provides a detailed description of the composition of the microbial communities resident in our gut, allowing us to focus on the biology of dominant bacterial species. Many of these bacteria are highly sensitive to dietary manipulation, particularly via specific non-digestible carbohydrates, as shown by human dietary interventions in vivo and studies on in vitro communities. Microbial metabolites such as short chain fatty acids play an important role in health maintenance and dietary changes have reproducible effects on the formation of fermentation acids such as butyrate that can be explained in part by shifts in the populations of particular phylogenetic groups of bacteria with gut pH as a likely key factor. Inter-individual variation in microbiota profiles also has an important impact on responses to dietary manipulation. New approaches both to prebiosis and probiosis, including the targeting of ‘beneficial’ groups of anaerobic bacteria, offer the potential to optimize health outcomes.