ImmuBoost contains a very high concentration of naturally occurring lactic acid producing bacteria. They have been prepared so as to provide a supplemental source of beneficial intestinal bacteria during stressful periods. The term "probiotic" is often used to describe products such as ImmuBoost that contain beneficial live bacteria. In ImmuBoost, the bacteria have been micro-encapsulated to ensure a stable, live product. ImmuBoost is a blue coloured paste, which makes it easier to identify which animals have been treated.