Gross But Useful? Mucus Disarms Microbes, Says Study

Runny noses, stuffy sinuses, and a cough that keeps you up at night - mucus can be annoying. But a new study from MIT shows the yucky stuff works hard to help keep you well.

Compounds in mucus called glycans disarm microorganisms and inhibit infections, according to the study published this month in the journal Nature Microbiology. Glycans are sugar molecules that perform a wide variety of biological functions.

How do glycans fight pathogens? According to the study, glycans inhibit bacterial communication and bust up biofilms, which are communities of bacteria involved in numerous diseases. Bacteria growing in biofilms are highly resistant to antibiotics, according to MedicineNet Chief Editor William C. Shiel Jr., MD, FACP, FAC.

The MIT team led by biochemist Katharina Ribbeck studied the effect of glycans on Pseudomonas aeruginosa, a type of opportunistic bacteria that grows in biofilms and may cause infections in those who have cystic fibrosis and other conditions.

The bacteria may affect those who are immunocompromised and it is a major cause of hospital acquired infections, Dr. Shiel said. The bacteria may affect those who suffer from burns, have indwelling catheters, or are on respirators.

The study revealed that when exposed to glycans, Pseudomonas aeruginosa behaves differently than it otherwise would, failing to produce toxins, kill host cells, or express genes required for bacterial communication. Ultimately the bacteria are rendered harmless by the addition of the glycans.
Glycans are present in mucus. But what exactly is mucus?

"Mucus is a normal, slippery, and stringy fluid substance produced by many lining tissues in the body," according to Melissa Conrad Stöppler, MD, of MedicineNet. It serves to lubricate and protect the lungs, sinuses, mouth, throat, nose, and gastrointestinal tract.

The average person produces 1 to 1.5 liters of mucus per day, Dr. Stöppler said. Mucus acts as a trap for bacteria, dust, and smoke, but beyond acting as a physical trap, Ribbeck's work shows that mucus actually changes bacterial behavior.

Ribbeck is now studying the effect of glycans on other microorganisms including Streptococcus and the fungus Candida albicans. Ribbeck hopes her research will lead to new treatments for antibiotic-resistant infections, such as an artificial mucus to treat conditions that arise from inadequate or ineffective mucus.

Source: MedicineNet Health News.