21 November 2012
Mucus is one of the less appreciated bodily secretions. Some bodily emissions generate pride, others eager anticipation, and others still a degree of fascination. Yet when a cold or flu strikes and mucus is being dispensed via your nostrils by the cup full, few people will speak up in admiration. Instead, it comes down to derisive comments to the effect of, “Oh, this damn mucus!” If that attitude strikes a chord in you then this story is for you because new research has shown that mucus has some antibacterial properties that could have wider applications.
Although you notice it in your nose when you have a cold, mucus is everywhere in your body. Mucus-producing cells line your mouth, nose, sinuses, throat, lungs, and gastrointestinal tract. Mucus acts as a protective blanket over these surfaces, preventing the tissue underneath from drying out. Every day you produce around 1.5 litres of fresh mucus but when you have a cold or flu or an allergy mucus production goes into overdrive. We know that mucus lubricates as well as providing a barrier to infection. Of course, it is one thing to say that mucus forms a barrier to infection but it is another thing to know how it does it and therefore be able to replicate that effect. Now, new research though has shown that mucus contains a substance which has a very specific way of fighting bacteria.
The new discovery came through exposing Pseudomonas aeruginosa bacteria to mucins taken from mucus. Mucins are long proteins with some sugar molecules attached. The researchers found that mucin will stop bacteria aggregating, or clumping together. This is important because immune cells are specialised to deal with one bacterium at a time. For bacteria to push through the mucus defensive line they must be able to clump together in order to attach to the surface of the tissue. Mucin stopped bacteria being able to stick together and if they can’t do that they can’t penetrate and they can’t create an infection. The advantage of mucins over antibiotics is because the bacteria are not being killed, just blocked, antibiotic resistance to mucins is less likely to become a factor.
The researchers believe that mucins could be used to prevent biofilms of bacteria building up on surfaces in medical and industrial environments. On a personal level they think that mucins could be used for people with reduced mucus production due to dehydration, chemotherapy, cystic fibrosis, or ageing. They suggest that the mucins could be administered in toothpastes or mouth-washes, although one wonders whether a toothpaste marketed as “now available with added mucus!” will find many takers. Still, marketer’s dream or not, it seems mucus does have some pretty powerful antimicrobial properties that could be used widely.
There you are, your mucus is snot so bad after all.