Shaping the human microbiome with prebiotic foods: current perspectives for continued development

The human gut microbiome is now seen as an important and modifiable contributor to host health. Recent post-genomic studies have highlighted the fact that an aberrant gut microbiota is a characteristic of many disease states, both chronic diseases of the gut (e.g. inflammatory bowel disease and colon cancer) and more systemic diseases (e.g. allergy, diabetes and obesity). Conversely, certain functional foods which mediate their physiological activities through the gut microbiota, have shown promise in reducing the risk of developing these diseases. Probiotics which aim to introduce exogenous beneficial bacteria into the gastrointestinal tract have proven effective in relief of lactose intolerance and the adverse gastrointestinal side-effects of antibiotic medication and in animal studies have been shown to protect against a chronic diseases by modulating immune and physiological processes. An alternastive or complementary approach to increase numbers of beneficial bacteria within the gut is dietary supplementation with prebiotic fibers. Prebiotics are non-digestible food components which through modulation of the gut microbiota, mediate improved host health. They have a proven track record in modulating the gut microbiome, with numerous studies showing that they can reproducibly increase relative numbers of intestinal Bifidobacterium spp. and are emerging as a particular set of functional foods with strong scientific support for their health promoting capabilities. The bifidobacteria are a group of bacteria increasingly recognised as an indicator or biomarker of gut health. In this review, we will discuss the various methods for selecting and testing of prebiotic functional foods and go on to discuss current challenges facing to probiotics and prebiotics field, recent novel insights and future prospects in a market increasing governed by the need to prove cause and effect for functional food health claims.