The Science
The Immune System
With beta-1,3/1,6-D-glucan



Animals are under constant attack by a threat of invasion by an array of microorganisms that plan to make the body their home and exploit it for food. To prevent the entry of of microorganisms and to destroy microorganisms that have gained access, the body has developed a complex series of complex and effective defenses.  These defenses are both passive and active. 

1. Passive defenses consist of :

a) The skin, which acts as a physical barrier to the entry of toxins and infectious agents.
b) The high acidity of the stomach, which can kill some ingested organisms. 
c) Chemicals, such as lysozyme and the complement system, which can kill bacteria
            directly. Lysozyme is secreted by many cells and is found in blood and tears;
            the Complement System is a series of about 30 proteins that can attach to bacteria and disintegrate

2. Active defenses are the real of the Immune System, which plays an important role in maintaining optimal health and longevity and is the body's primary defense against a wide variety of bacteria, viruses, fungi and other organisms that have gained access to the body as well as cancerous cells.

The Immune System can be separated into two distinct, but related, branches:
  a) Innate Immune System: The granulocyte, monocyte/macrophage cells branch.
        The granulocytes and monocyte/macrophages form the first line of adaptive immune defense.
These cells are recruited into action when they recognize foreign invaders, such as microbes, toxins,
tumor cells, etc.
b) Aquired Immune System: The T and B cells branch. T cells and B cells are
          called into action by various specific signals.  

This video represents a macrophage (big eater) eating and destroying viruses.


The first cells to respond to an insult are the neutrophils (a type of ganulocyte) followed closely by the macrophages. If their response is inadequate to fight off the invasion, B cells and T cells are called in to join the battle. The B and T lymphocyte response can be humoral or cell-mediated. In the humoral response, B lymphocytes produce specific molecules (antibodies) that recognize and react to the specific challenge. Antibodies are especially effective to fight bacterial infections. In the cell-mediated response, T lymphocytes recognize foreign organisms as well as cells that have been invaded by viruses or that have transformed to cancerous cells and initiate a cellular response through chemical mediators called cytokines. The cell-mediated response is especially efficient against tumor cells, fungi and viruses.  
The Immune System has been developed to prevent an organism from becoming victim of microbes and toxins that are present in the environment.  Some cells of the Immune System are placed into action as soon as the presence of a foreign agent is perceived; the cells, namely macrophages, granulocytes, and Natural Killer cells, form the "innate defenses".  T and B cells are placed into action only after specific signals are perceived and form the "acquired defenses". 

The Immune System of man and animals is a complex system, which is exquisitely sensitive to respond to many environmental insults.  At the slightest provocation the Immune System begins a series of defensive actions aimed at destroying the offender and repairing any damage that may have occurred.  In most cases the Immune System is very effective in fighting off infecting organisms.  However, in an environment that is highly contaminated with bacteria, viruses and other germs (such as stables), or when the environment is suppressive to the immune system, such as in crowding, by chemicals to diets, by the presence of specific viruses, the Immune System may not be sufficient to defeat the offending organisms.   

Are there any means to increase the ability of the Immune System to combat infections?  Yes!  A substance purified from Baker’s yeast (Saccharomyces cereviciae) has been shown by many scientists to be very effective in increasing the ability of the Immune System to fight infections and maintain the organism healthy.  This substance is called beta-1,3/1,6-D-glucan.

Beta-1,3/1,6-D-glucan activates the Immune System of humans and animals by recognizing and binding to specific receptors on the surface of macrophages, neutrophils and NK cells. The binding of beta-1,3/1,6-D-glucan to the cell surface receptors of these cells initiates a series of reactions that result in the enhancement of the activity of these cells, specifically these cells will become much more aggressive in the killing of microbes and in the production of factors that are released into the blood stream to recruit other cells of the immune system to combat any foreign substance or organism.  Thus, beta-1,3/1,6-D-glucan administered to animals increases resistance to bacterial and viral infections, to radiation damage, and increases the production of red blood cells, platelets and lymphocytes. In addition new studies we have done show that beta-1,3/1,6-D-glucan suppresses the inflammatory response.

EquiHealth Inc has developed a process to purify large quantities of biologically active beta-1,3/1,6-D-glucan from yeast.   The beta-1,3/1,6-D-glucan has been used in laboratory studies to show that it activates the immune system, and in field trials to show that it is effective in maintaining the health of horses, poultry, cattle, pigs, shrimps as well as humans. 


All vertebrate animals, including man, live in a close relationship with a large number of bacteria (flora) found on the skin, in the mouth and in the gastro-intestinal tract. The relationship between animals and bacteria is referred to as commensalisms and the bacteria are referred as commensal bacteria. The largest number of commensal bacteria is found in the gastrointestinal tract with about 500 different bacterial species, some of which have important functions that include stimulation  of the immune system and aiding digestion and some of which may be harmful, such as Helicobacter pylori, which is the cause of most ulcers in humans and animals.  The bacteria most commonly used in probiotic preparations belong to the genera of Lactobacillus, Bifidobacterium, Escherichia, Enterococcus, and Bacillus.

The use of antibiotics and other drugs cause changes in the type of bacteria in the gastrointestinal tract by killing the bacteria and allowing often harmful bacteria to colonize the gastrointestinal tract.  To re-establish a beneficial flora it is necessary to introduce in the gastrointestinal tract as many good bacteria as possible to re-balance and exclude harmful bacteria.

A number of studies have shown that the introduction of probiotics in the gut can be very effective in alleviating a number of clinical conditions- ranging from necrotizing enterocolitis, antibiotic associated diarrhea, colitis, ulcers (Helicobacter pylori infections), and even surgical infections.  Since probiotics have been found to inhibit the growth of Helicobacter pylory in vitro, to reduce the number of H. pylori associated with gastric inflammation in animals and to improve H. pylori associated gastritis  (for more information see: Lesbros-Pantoflickova D, Corthesy-Theulaz I, Blum AL. Helicobacter pylori and probiotics. J Nutr 2007;137:812S-8) it is important that horses, which are subject to stress and ulcers, be administered probiotics in doses sufficient to displace the ulcer-forming Helicobacter pylory .   

Another significant beneficial effect of probiotics is the treatment and prevention of diarrhea and especially antibiotic associated diarrhea. Antibiotic associated diarrhea is accompanied by severe side-effects including electrolyte imbalance, dehydration, pseudo-membrane colitis and toxic megacolon (for more information see: D'Souza AL, Rajkumar C, Cooke J, Bulpitt CJ. Probiotics in prevention of antibiotic associated diarrhea: meta analysis. BMJ 2002;324:1361).  

Probiotics may benefit athletic performance by maintaining GI function and health, preventing the immunosuppressive effects of intense exercise, and reducing susceptibility to illness.  Many studies indicate that probiotic supplementation may reduce the number, duration and severity of illness compared with placebo supplements.  In one study of 20 professional runners the use of probiotics reduced the number by 50% the number of days with respiratory symptoms over a four month winter training season. Illness severity was also lower for episodes occurring during the supplementation period (For additional information see: Cox AJ, Pyne DB, Saunders PU, and Fricker PA. Oral administration of the probiotic Lactobacillus fermentum VRI-003 and mucosal immunity in endurance athletes. Br J Sports Med 2008).  In another study 22 endurance athletes were given probiotics and 22 served as controls. After four weeks of supplementation with probiotics, the athletes were tested after a 60-minute endurance session. The probiotics group exhibited a smaller post-exercise decrease in the level of circulating natural killer (NK) cells, which are immune cells that play an important role in fighting infections.  

A problem with many supplements containing probiotics in the equine market is that the number of probiotics recommended is too low.  For man to obtain the healty benefits of probiotic supplementation, a dose of five billion colony forming units a day has been recommended   For a horse it is necessary to increase the dose to 25-50 billion colony forming units/day. 

EquiStar™  has 50 billion colony forming units/day and the immunostimulant beta-1,3/1,6-D-glucan, giving the horse the reqired amount of probiotics and in addition stimulates the immune system to allow the horse to perform at its peak efficiency.

For horses suffering with gastrointestinal problems, such as ulcers, colitis, gastritis, the probiotics in EquiStar™ will displace the “bad” bacteria that cause these problems, while the beta glucan enhances the ability of the immune system to kill the bad bacteria that may not be displaced by the probiotics.

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