OCT 15, 2019 08:46 AM PDT

The Antimicrobial Power of Mucus is Revealed

WRITTEN BY: Carmen Leitch

Mucus lines our respiratory system, and the urinary and digestive tracts. We produce several liters of mucus every day to cover more than 200 square meters in the human body. While it’s known to be a lubricant and to act as a physical barrier against invading pathogens, scientists have found evidence suggesting that it can prevent infections in other ways. Now researchers at the Massachusetts Institute of Technology (MIT) have found that a group of sugar molecules found in mucus, called glycans, can stop bacteria from signaling to each other and halt the formation of dangerous, tough biofilms. The findings have been reported in Nature Microbiology.

Image credit: Pixabay

"What we have in mucus is a therapeutic gold mine," said Katharina Ribbeck, the Mark Hyman, Jr. Career Development Professor of Biological Engineering at MIT. "These glycans have biological functions that are very broad and sophisticated. They have the ability to regulate how microbes behave and really tune their identity."

Ribbeck and others have shown that mucus can stop microbes from binding to surfaces. In this work, the researchers wanted to know more about whether glycans are part of the reason why mucus disrupts microbial behavior. Glycans can attach to mucins, the gelatinous building blocks of mucus, to generate a structure shaped like a bottlebrush. That led Ribbeck to hypothesize that the glycans were having an antimicrobial effect.

The scientists focused on how glycans were interacting with an opportunistic microbial pathogen called Pseudomonas aeruginosa. The bacterium commonly causes serious infections in people with weak immune systems and cystic fibrosis patients. The investigators found that when bacteria were exposed to glycans isolated from mucus, they were disarmed; the microbes stopped attaching to or killing host cells, halted production of toxic molecules, and microbial genes that are involved in bacterial communications weren’t expressing. If burn wounds are treated with mucins and mucin glycans, the growth of bacteria is reduced.

"We've seen that intact mucins have regulatory effects and can cause behavioral switches in a whole range of pathogens, but now we can pinpoint the molecular mechanism and the entities that are responsible for this, which are the glycans," Ribbeck explained.

The researchers now plan to study the impact of individual glycans out of hundreds that can be found in mucus. They also want to know more about how glycans affect other kinds of pathogens, including the Candida albicans fungus and Streptococcus bacteria. They already know that glycans can stop Streptococcus from sharing genes, a primary way that drug resistance spreads among microbes.

Scientists, including Ribbeck, are also looking into the development of artificial mucus, which might be a new approach to fighting pathogens that does not involve traditional antibiotic drugs.

"What we find here is that nature has evolved the ability to disarm difficult microbes, instead of killing them. This would not only help limit selective pressure for developing resistance, because they are not under pressure to find ways to survive, but it should also help create and maintain a diverse microbiome," noted Ribbeck. Glycans may help regulate that microbial population.

"This is a theme that is likely at play in many systems where the goal is to shape and manipulate communities inside the body, not just in humans but throughout the animal kingdom," Ribbeck concluded.


Sources: AAAS/Eurekalert! via MIT, Nature Microbiology

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
NOV 18, 2019
Microbiology
NOV 18, 2019
Using Peptides to Remodel the Microbiome
Now that we know so much more about the bacteria we carry in our bodies, it may be possible to start using that bacteria to improve our health....
NOV 18, 2019
Genetics & Genomics
NOV 18, 2019
Gut Microbes can Significantly Impact Host Gene Expression
We all carry a vast number of microbes with us, and the microbial community in the gut is closely linked to our health and well-being....
NOV 18, 2019
Microbiology
NOV 18, 2019
Antibiotic Resistance Rises in Wild Dolphins
Antibiotic resistant bacteria are considered a major threat to public health, which is expected to get more serious....
NOV 18, 2019
Immunology
NOV 18, 2019
This is How Your Immune System Responds to Ebola Vaccination
Vaccines to prevent Ebola are still in their infancy, with experimental-only versions being used only in the most dire of instances. In a new study, scient...
NOV 18, 2019
Microbiology
NOV 18, 2019
Measles Can Wipe Out the Memory of the Immune System
Researchers have learned how the measles vaccine can provide an additional layer of protection against more than just the measles....
NOV 18, 2019
Cancer
NOV 18, 2019
Specific gut bacteria linked to bowel cancer
New research suggests that the presence of a certain kind of gut bacteria can increase the risk of bowel cancer by as much as 15%. The research is importan...
Loading Comments...