The mammalian gastrointestinal tract contains a large and diverse population of commensal bacteria and is also one of the primary sites of exposure to pathogens. How the immune system perceives commensals in the context of mucosal infection is unclear. Here, we show that during a gastrointestinal infection, tolerance to commensals is lost, and microbiota-specific T cells are activated and diffe...

background bottled mineral water is generally considered more pure than tap water in developing countries. immunocompromised patients and those with co morbid conditions are often offered bottled mineral water since they are believed to be safer. the present study was designed to determine the risk of common bacterial contamination of commercially available bottled mineral water in iran. materi...