The Role of Mucus in Digestion

Mucus plays a hugely important role in digestion, in addition to helping establish the overall health of other areas of your body.

In this article we’ll focus just on how mucus helps in mechanical digestion, and why you need to make sure that your body has a suitable amount.

Why does mucus help?

Your body makes about a liter of mucus every day, and some of it may be for the benefit of your bowels. The first question to answer regarding mucus and its role in digestion is why mucus is a helpful substance. Mucus, though it doesn’t look like it, helps destroy bacteria and viruses, in addition to trapping particles, preventing water loss, lubricating the movement of materials through your body, and protects all the surfaces it touches from damage.

You have mucus in your mouth, in the form of saliva, and even in your eyes. The viscosity of the mucus depends on where it’s located in your body. In your nose, for examples, it’s thicker in order to fight against the potential viruses, dirt, and other irritants which can easily enter the nose. With your digestive tract, however, mucus is a bit different.

How does mucus help digestion?

Your stomach is lined by a protective layer of mucus, which is responsible for creating the enzymes that help your body digest proteins. Additionally, the mucus lining your stomach helps prevent your stomach lining from the negative effects of excessive exposure to acid or pepsin.

Now, as for your digestive tract specifically – mucus helps there as well. Since mucus works to lubricate items in your body for easy movement from one area of the body to another, it’s important to have enough in your intestinal tract.

The intestines can easily be perforated or otherwise harmed by sharp objects you’ve eaten that haven’t been completely ground down yet (potato chips, crackers, etc.). Mucus coats these objects so they flow through your intestines at a much more productive rate, ensuring that your body is able to process the food you eat as efficiently as possible.

According to a 2013 study published in Science, mucus may hold the key to understanding digestive health and help explain inflammatory bowel disease (IBD) — more so, it may even be a treatment for it.

“We all live with trillions of bacteria inside our digestive system,” said Andrea Cerutti, MD, PhD, a professor in the department of medicine at the Immunology Institute at the Mount Sinai Icahn School of Medicine in New York City. “We have more bacteria than we have cells in our body. Some of these bacteria would kill us if they were free in another part of our body. We wanted to know what role mucus plays in allowing us to live in peace with all these bacteria.”

Mucus from beginning to end:

Now that you can see how mucus is important in many different aspects of your health, let’s look at the process it plays from beginning to end in your digestive system.

First, the saliva in your mouth (a form of mucus) breaks down your food, fights bacteria in your mouth, and removes plaque from your teeth. Then the mucus lining your throat lubricates the food as it enters your stomach.

There, the protective mucus membrane on the lining of your stomach protects it from acid exposure. Once it’s done in your stomach, the food moves to your intestines where it’s once again coated in mucus to move freely through your entire digestive tract.

It may not be outwardly apparent, but without mucus it’s easy to see that our bodies wouldn’t function as well as they could.

Mucus: Intestinal Inflammation Fighter

There are dendritic cells that line the intestines and allow the immune system to tolerate bacteria and allergens without causing inflammatory response.

The new research shows that a component of mucus called mucin type 2, or MUC2, is picked up by dendritic cells. MUC2 then signals the dendritic cells to tolerate bacteria or antigens. In other words, mucus is not just a protective coating; it also plays an important role in regulating digestive inflammation.

The researchers used mice, pigs, and human intestinal cells to demonstrate that MUC2 is the protein that communicates with dendritic cells, Cerutti said.

Mice that were genetically engineered to have less mucus, less tolerance, and more inflammation were given mucus from healthy mice. “When we used reconstituted healthy mucus,” he said, “we were able to restore tolerance in the mice with inflammation.”

Treatment for Crohn’s Disease and Ulcerative Colitis?

Crohn’s disease and ulcerative colitis affect about 1.4 million Americans. Crohn’s disease can cause inflammation anywhere in the digestive tract, while ulcerative colitis occurs only in the colon. Both can cause symptoms like fever, diarrhea, pain, and weight loss.

The researchers believe that if something lessens the quality of intestinal mucus, the immune system may then not be able to endure bacteria without an inflammatory reaction, which could then lead to Irritable Bowel Syndromes or IBS.

So if altered mucus contributes to the cause of IBS, could healthy mucus help treat it? Cerutti and his colleagues think there’s a good chance it can. Cerruti also points to the potential that healthy mucus may have in curbing food allergies.

We all have heard of probiotics and how good they are in combating the “bad bacteria” in our intestinal microbiome so that it may bring back the balance of healthy flora population in our intestines. Many of the well known probiotics for the intestines are of lactobacillus and bifidobacterium strains. As a result, probiotic products have become more popular than ever and they mostly deals with intestinal health.

Oral Treatment with Probiotic S. Salivarius?

However, as we mentioned before, digestion begins in the mouth and probiotics are there in the saliva mucus as well. Specifically, streptococcus salivarius K12 has been isolated and found to be of particular benefit to our oral and overall health.

For example, S. salivarius has been shown in vitro to have inhibitory activity against S. pyogenes, the principal causative agent of streptococcal pharyngitis. A study showed that children who frequently experienced clinically confirmed sore throats were significantly less likely to have BLIS-producing S. salivarius than children who had not experienced sore throats in the past 3 years. Recent, as yet unpublished, studies have also demonstrated that the use of one lozenge a day containing 1 billion viable cfu of strain K12, is sufficient to achieve oral cavity colonization in the majority of subjects [WESCOMBE PA ET AL., UNPUBLISHED DATA]. Further evidence for the protection afforded by strain K12 against streptococcal pharyngitis was gathered during a small preliminary trial in which 24 children with a history of recurrent tonsillitis (0.33 episodes per month) received daily doses of either strain K12 or a placebo.


Future research may involve learning about what goes wrong with mucus in IBD and how to reconstitute healthy mucus into a form of treatment. Studying, reconstituting, or artificially creating mucus to be used as medicine is complicated, though. MUC2 is a complex molecule — “a big protein decorated with lots of sugars,” Cerutti said. “So we have a lot to learn.”

Source: Nature’s Sunshine Products Posts and


Posted by Paul

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