The study showed that healthy mice fed with Lactobacillyus rhamnosus GG (LGG) bugs demonstrated an immune response that stimulated an increase in bone density. The effect seen in young female mice is linked to a metabolite called butyrate or butyric acid -- a type of fatty acid produced by gut bacteria. This in turn activated bone-enhancing immune cells including regulatory T cells the researchers said. The significance of the study is that probiotics are at least in mice an effective means to increase bone density said Roberto Pacifici from the Emory University in the US. Our findings will need to