Probiotics and prebiotics in intestinal health and disease: from biology to the clinic

Probiotics and prebiotics are microbiota-management tools for improving host health. They target gastrointestinal effects via the gut, although direct application to other sites such as the oral cavity, vaginal tract and skin is being explored. Here, we describe gut-derived effects in humans. In the past decade, research on the gut microbiome has rapidly accumulated and has been accompanied by increased interest in probiotics and prebiotics as a means to modulate the gut microbiota. Given the importance of these approaches for public health, it is timely to reiterate factual and supporting information on their clinical application and use. In this Review, we discuss scientific evidence on probiotics and prebiotics, including mechanistic insights into health effects. Strains of Lactobacillus , Bifidobacterium and Saccharomyces have a long history of safe and effective use as probiotics, but Roseburia spp., Akkermansia spp., Propionibacterium spp. and Faecalibacterium spp. show promise for the future. For prebiotics, glucans and fructans are well proven, and evidence is building on the prebiotic effects of other substances (for example, oligomers of mannose, glucose, xylose, pectin, starches, human milk and polyphenols). The gut microbiota has been implicated in a range of diseases. This Review describes current understanding of probiotics and prebiotics as a means to manage the microbiota to improve host health, including mechanisms of actions and potential for clinical use. Key points The human gut microbiota is integral to health and is associated with a variety of diseases. Therapeutic and prophylactic effects of some probiotics and prebiotics for a variety of gut-related disorders might be, at least in part, mediated through modification of the microbiota and/or its function. Probiotic microorganisms act via a variety of means, including modulation of immune function, production of organic acids and antimicrobial compounds, interaction with resident microbiota, interfacing with the host, improving gut barrier integrity and enzyme formation. Prebiotics are substrates that are selectively utilized by host microorganisms conferring a health benefit; prebiotic effects include defence against pathogens, immune modulation, mineral absorption, bowel function, metabolic effects and satiety. Use of some probiotics and prebiotics is justified by robust assessments of efficacy, but not all products have been validated; the goal is evidence-based use by healthcare