Use of whole cells of bacteria from the genera of aerobic organisms in the order of Actinomycetales in the manufacture of a medicament for the treatment or prevention of Type II diabetes and/or obesity and methods of treating or preventing Type II diabetes and/or obesity in a subject by administering an effective amount of a composition comprising a whole cell of a bacterium from a genera of aerobic organisms in the order of Actinomycetales to said subject. Preferably the bacteria is from one or more of the following genera for example: Gordonia, Rhodococcus, Tsukamurella, Nocardia, Dietzia and Mycobacterium.