title: Probiotic lactic acid bacteria - the fledgling cuckoos of the gut?
abstract: It is tempting to look at bacteria from our human egocentric point of view and label them as either 'good' or 'bad'. However, a microbial society has its own system of government - 'microcracy' - and its own rules of play. Lactic acid bacteria are often referred to as representatives of the good ones, and there is little doubt that those belonging to the normal intestinal flora are beneficial for human health. But we should stop thinking of lactic acid bacteria as always being 'friendly' - they may instead behave like fledgling cuckoos.
authors.affiliation: Unger-Vetlesen's Institute, Lovisenberg Diakonale Hospital, Oslo, Norway; arnold.berstad@k2.uib.no.
authors.forename: Arnold
authors.initials: A
authors.lastname: Berstad
authors.affiliation: Unger-Vetlesen's Institute, Lovisenberg Diakonale Hospital, Oslo, Norway.
authors.forename: Jan
authors.initials: J
authors.lastname: Raa
authors.affiliation: Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Stockholm, Sweden.
authors.forename: Tore
authors.initials: T
authors.lastname: Midtvedt
authors.affiliation: Unger-Vetlesen's Institute, Lovisenberg Diakonale Hospital, Oslo, Norway.
authors.forename: Jørgen
authors.initials: J
authors.lastname: Valeur
keywords: bacteriocins; irritable bowel syndrome; lactic acid bacteria; obesity; probiotics