Bifidobacteria are Gram-positive anaerobic bacteria, found naturally in the gut of humans and other mammals. They are widely used as probiotic organisms in a vast array of formulations for the prevention, alleviation, and treatment of many intestinal disorders. However, bifidobacteria are fastidious microorganisms and are difficult to study in the laboratory, so until recently, understanding of their genetics lagged behind that of other high GC content Gram-positive bacteria. The application of modern whole genome approaches to bifidobacteria research has changed all of this, permitting the...