Overview of antimicrobial proteins called lysozymes

Lysozymes, also known as muramidase, are the most important bactericidal proteins of the mucosal immunity. They are referred to as the ‘body’s own antibiotic’, since they get rid of pathogens. Mucosal surfaces in the body, such as digestive tract, eye conjunctiva, airways, and ducts of exocrine glands represent the largest area of exposure to germs. The mucosal immune system provides a first line of defense against these invading pathogens. Therefore, the protective properties of the mucous membranes are dependent on the action of various antimicrobial proteins, including lysozyme. These magnificent proteins were discovered in 1922 by Nobel’s laureate Sir Alexander Fleming, from the hen egg white.

Sources of production

Naturally, lysozymes are manufactured in our bodies by the secretory cells of the epithelia, lining the respiratory mucosal surfaces, the middle ear and eustachian tube. Lysozymes are also found in saliva, tears, mother’s milk, digestive system, and the reproductive organs.

Impairment of mucosal immunity

Development of mucosal immunity is affected by exposure to infections and to a lesser extent cigarette smoke, stress and dryness. The decrease in intestinal mucosal immunity with advancing age explains the increased susceptibility to infectious diseases. Smokers have been found to be mucosal immunodeficient. Mounting evidence has also indicated the negative role of stress on salivary lysozyme and immunoglobulin A-level. Last but not the least, low humidity during winter can dry out mucous membranes, reducing the protective effects of the mucous membrane and its supply of anti-microbial proteins (AMPs).

Lysozymes, antimicrobial proteins

Lysozymes protect us from bacterial infections by attacking the cell wall of different species of bacteria ranging from bacilli, staphylococci, and streptococci, ultimately leading to their demise. Apart from viruses and bacteria, lysozymes are also efficacious against fungi and fungal infections.

Lysozymes fight viral and bacterial infections caused by flu and cold, sore throat, fever blisters, etc. It is found that they are effective in reducing systemic and local inflammation. They can be applied topically to heal lesions and wounds. The presence of lysozymes in mother’s milk is one of the reasons why breast-fed infants are immunized against inflammatory processes and gastrointestinal disturbances in contrast to their formula-fed counterparts.

Lysozymes mode of action in the mucosa

There are several mechanisms by which lysozymes disrupt the pathogenic activity and reduce inflammation.

  • The antimicrobial proteins, lysozymes, compete directly with the pathogenic microorganisms for epithelial attachment sites in the GI tract, thereby preventing the attachment and colonization of the gastrointestinal tract by way of adhesion and clearance of bacteria.
  • Lysozymes bind to and destruct the cell walls of bacteria, triggering their autolysis and eventually cell death.
  • Lysozymes increase the activity of other immune factors such as IgA and AMPs in the mucous membrane to further restrict the entry and attachment of bacteria and viruses.

Need to supplement

Enzyme production diminishes with aging. As a consequence, nutrient’s malabsorption, chronic ill-health conditions and tissue breakdown increases to a much greater extent. It is therefore, advisable that one should include enzyme supplements in the diet in order to maintain optimum food absorption.  A report of JEFCA-Joint FAO/WHO Expert Committee on Food Additives has clearly designated the lysozymes obtained from edible animal tissue as class I enzyme, thus food.  These antimicrobial proteins can be replenished through food or supplements. Some digestive enzyme blends, like Celluzyme, contain lysozymes to support the intestinal tract against bad bacteria colonization.



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*None of the statements above have been evaluated by the FDA. This product is not intended to diagnose, treat, cure or prevent disease.