2021-02-27 19:43 B. bifidum is a Gram-positive bacterium that is not motile, anaerobic, and not spore-forming. The bacterium is rod-shaped and can be found living in clusters, pairs, or even independently. The majority of the population of B. bifidum is found in the colon, lower small intestine, breast milk, and often in the vagina. B. bifidum is an essential bacteria found in the human intestine. When it is low or absent all together in the human intestine, it is an indication of being in an unhealthy state.