The immune system is the intricate network of cells, tissues, and organs, including the intestine, that protect us against disease. Up to 70% of the body’s immune system response originates in the intestine. Because of its direct contact with external invaders capable of inducing infections, the intestine must be able to adequately defend the body. It plays a major role in an individual's immunity. The intestine is very rich in antibody-producing lymphocytes that are found under the intestinal mucous membrane. A person's normal bacterial flora also plays a part in immune response by providing a source of energy for the epithelial cells of the intestinal lining to regenerate themselves when depleted.

Probiotics strengthen the body’s overall immune system response while they specifically reinforce intestinal mucous membrane immunity. The body’s immune system defenses include both innate and acquired responses. Probiotics increase production of T & B lymphocytes that produce antibodies, coordinate the immune system response, and directly attack infected cells¹. Antibodies such as IgM, IgA and IgG serve the body’s acquired response to pathogens. IgM is the antibody first produced by the body in response to infection - it causes other immune system cells to take action - the IgA antibody protects the mucous membranes, and IgG fights infections in body fluids².

Inflammation is part of the body's innate immune responses to unwanted microorganisms and is characterized by the recognition and destruction of foreign bodies. Phagocytes are the white blood cells that carry out this process of fighting infections and digesting unwanted foreign particles. The consumption of lactobacillus stimulates phagocytic activity. Probiotics themselves do not provoke a significant inflammatory response. Indeed, probiotics regulate the inflammatory reactions of intestinal mucous, and studies have shown they can restore the normal balance between the signaling molecules that increase or decrease inflammation, IL-10 & IL-12³. Maintaining a healthy intestinal flora balance sets the stage for the immune system to respond more effectively and carry out its vital defensive role.

• 1. Resta SC. Effects of probiotics and commensals on intestinal epithelial physiology: implications for nutrient handling. J Physiol. 2009. 587:4169-4174.
• 2. Perdigon G et al. Study of the possible mechanisms involved in the mucosal immune system activation by lactic acid bacteria. J Dairy Sci. 1999. 82:1108-1114.
• 3. Mengheri E. Health, probiotics, and inflammation. J Clin Gastroenterol. 2008. 42 (suppl. 3):S177-178.