A family of oligosaccharides that can be produced by man in commercial quantities via certain yeast cells. When consumed (e.g., by livestock), mannose sugars in the MOS stimulate the liver to secrete the mannose-binding protein. Mannose binding protein enters the digestive system and binds to the (mannosecontaining) capsule (surface membrane) of pathogenic bacteria. That binding to pathogens triggers the immune system’s complement cascade to combat those pathogenic bacteria.