You know that yellow gooey stuff that you blow out of your nose during allergy season? That’s mucus and although it may look and feel disgusting, it is actually a vital part of our body. Recent studies have looked into the the variety of roles that mucus plays in protecting the body and introduced new focuses. Mucus is composed of water, lipids, and glycoproteins called mucins. There are many different types of mucins that give mucus its different properties. For example, the mucus in our eyes that keeps them from drying out is composed of different mucins than the mucus in our intestine. The gel-like mucus contains mucins called MUC5BC and MUC5A, which help to clear out our airways by lining our cells so that bacteria cannot penetrate them. However, infections can also cause a buildup of mucus, since the mucins are produced at a faster rate in order to fight the bacteria. We sneeze out all of that mucus when we are sick in order to clear out all of that excess mucus.
Remember those kids in the back of your kindergarten class who used to eat their own boogers? There are actually bacteria in our intestines that feed on the glycans on mucins as an energy source. Even this may seem detrimental to the mucus in our intestines, the bacteria actually secrete butyrate, which the gut cells in our intestines use to manufacture more mucins.
Mucins risk their lives in order to insure that our cells are protected from harmful viruses and bacteria. Recent research has shown that the glycans that are attached to mucins have the ability to stop the spread of pathogens within the body. Mucins often act as decoys when bacteria try to bind to cells. The bacteria bind to certain molecules on the surface of the cell, which includes glycans. Instead of binding to the cell, the bacteria bind to the glycans from the mucins and the mucin takes the bacteria into a pool of gastric acid along with itself. A true hero!
Since mucins are so essential to the fight against the harmful pathogens invading our body, scientists are researching the molecular make-up of mucins in order to one day create a synthetic mucin. These could be used to repair mucus linings that are ineffective in protecting our cells.