|| Checking for direct PDF access through Ovid
The human gut microbiome is now seen as an important and modifiable contributor to host health. Recent post-genomics studies have highlighted the fact that an aberrant gut microbiota is a characteristic of many chronic gut-related diseases (e.g. inflammatory bowel disease and colon cancer) and systemic diseases (e.g. allergy, diabetes and obesity). Conversely, certain functional foods that 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 been proven to be effective in the relief of lactose intolerance and adverse gastrointestinal side effects associated with antibiotic medication. In animal studies, probiotics have been shown to protect against chronic diseases by modulating immune and physiological processes. An alternative or complementary approach to increasing the numbers of beneficial bacteria within the gut is through dietary supplementation by means of prebiotic fibres. Prebiotics are non-digestible food components that improve the host's health through modulation of the gut microbiota. 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. In this review, we will discuss the various methods for selecting and testing prebiotic functional foods and the current challenges facing probiotics and prebiotic development. Recent novel insights and future prospects in a market increasingly governed by the need to prove cause and effect for functional food health claims will also be discussed.