Roseburia hominisRoseburia hominis.A first aspect of the invention relates to the bacterial species for use in: • regulating the immine system of a subject • treating an immune disorder • treating an intestinal disorder • improving intestinal microbiota • regulating the innate immune system of a subject • regulating the adaptive immune system of a subject • regulating appetite in a subject • promoting Tregs and immune tolerance • promoting gut health in a subject and/or • maintaining immune homeostasis in a subject. Further aspects of the invention relate to compositions comprising
