Why Lysine Lysine is an essential amino acid (protein building block) needed by the body. It supports proper nitrogen balance and absorption of calcium. Lysine also supports the production of antibodies, hormones, enzymes, and muscle protein. It supports carbohydrate metabolism, energy production, and cold and canker sores. Why a probiotic with your lysine We combined it with a probiotic, Bifidobacterium bifidum (Providing 1 billion live organisms at time of manufacture) to provide the optimal environment in the gut for your lysine to absorb!. For immunity and for general health, try Maxi Lysine Complex.