RT info:eu-repo/semantics/article T1 Human colon-derived soluble factors modulate gut microbiota composition A1 Hevia, Arancha A1 Bernardo Ordiz, David A1 Montalvillo Álvarez, Enrique A1 Al-Hassi, Hafid O. A1 Fernández Salazar, Luis Ignacio A1 Garrote Adrados, José Antonio A1 Milani, Christian A1 Ventura, Marco A1 Arranz Sanz, Eduardo A1 Knight, Stella C. A1 Margolles, Abelardo A1 Sánchez, Borja K1 Sistema inmunológico K1 Colon K1 3205 Medicina Interna AB The immune system of the gastrointestinal tract (GIT) is exposed to a large amount of foreign but harmless antigens typically derived from nutrients and commensal bacteria but sometimes deleterious when derived from infectious bacteria or viruses. Nevertheless, the GIT immune system is effective in discriminating between maintaining immune tolerance against diet and/or commensal derived antigens, and initiating immune responses against harmful invading pathogens (1). IL-15 is one of the cytokine of the innate immune response, regulating both T and natural killer (NK) cell activation and proliferation (2). The commensal microbiota plays a central role in modulating the outcome of immune responses in the GIT keeping immune homeostasis in health (3). Indeed, germ-free animals have an immature immune system and can develop inflammation, which is reversed once the microbiota is conventionalized (4). The commensal microbiota modulates several aspects of the host including the physiology and/or its nutritional status. The microbiota is also related to several diseases affecting the gut, like in inflammatory bowel diseases (IBD), and also influences diseases in distant organs (5–8). On turn, chronic gut inflammation such as happens in IBD is a risk factor for colorectal cancer. This is apparently a consequence of a high and persistent inflammation at the mucosa levels (9). PB Frontiers Media SN 2234-943X YR 2015 FD 2015 LK http://uvadoc.uva.es/handle/10324/41878 UL http://uvadoc.uva.es/handle/10324/41878 LA eng NO Frontiers in Oncology, 2015, vol. 5, 86 NO Producción Científica DS UVaDOC RD 29-abr-2024