Bifidobacterium Agar, Modified is recommended for the isolation of the Bifidobacterium species from faeces or stool specimens. The medium is also supplemented with propionic acid, and the pH of the medium is 5.0. Propionic acid is inhibitory to fungi and many bacteria other than Bifidobacteria, such as intestinal Bacteroides and Enterobacteriaceae. The low pH of the medium further contributes to inhibit other predominating organisms of human faeces, such as Bacteroides and Eubacterium species. It contains lactulose, a sugar used as a prebiotic that is preferably fermented by Bifidobacteria. Glucose is a carbon source. Riboflavin is a vitamin for many Bifidobacteria.