Neuraminic acid was known first as sialic acid

Neuraminic acid, or sialic acid as it was first called, is a monosaccharide with nine carbons. It has a negative electric charge which gives compounds containing it a negative charge. This is useful for keeping molecules like red blood cells from getting to near to each other. The negative charge on the surface glycoproteins repels the red blood cell from each other or from the walls of blood vessels which also have compounds containing sialic acid.

Mature red blood cells have an active life for about seven days.  White blood cells remove older red blood cells and de-sialylation of the surface proteins is one way the older cells are identified. Cancer cells with the ability to produce excess surface sialyation may have an increased chance to metastasize and turn up somewhere else in the body. [13]

Our bodies need to be healthy and well enough nourished overall to keep the whole system working. The neuraminic acid is produced within our cells from other chemicals in a series of membranous channels called the endoplasmic reticulum and the golgi apparatus. The channels have embedded enzymes along the way somewhat like an assembly line in a factory. We can not just eat more sialic acid in our diet and have it show up on our cell surfaces – we have to be healthy enough and well enough nourished over all in order to be able to manufacture our own supply of sialic acid.

Therapeutic glycoproteins are being developed and the problem of just the right amount of sialylation is one of the hurdles being studied. [2] In addition to the negative charge sialic acid tends to stabilize and stiffen the protein portion of the glyco-compound.  The proteins that line vessels were described to be somewhat like bottle-brushes; the protein being somewhat like the sturdy wire handle of the brush and with the negatively charged sialic acid acting as bristles that electrically repel other molecules of sialic acid. [1]

/This article was originally posted on 8/21/2013./ /Disclaimer: Information presented on this site is not intended as a substitute for medical care and should not be considered as a substitute for medical advice, diagnosis or treatment by your physician./

More recent research from the scientists at the University of Zurich, regarding sialic acid, found an association between the presence of autoimmune disease and reduced levels of sialic acid on the individual’s antibodies, which are important for the body’s immune cells to be able to recognize and remove infected or foreign or decaying cells: “Specific Sugar in Antibodies Structure Determines the Risk of Autoimmune Diseases,” Oct. 7, 2015, []


  1. S.A. Brooks, M. V. Dwek, U. Schumacher, Functional and Molecular Glycobiology, (BIOS Scientific Publishers, Ltd., 2002), Amazon.
  2. Bork K, Horstkorte R, Weidemann W., “Increasing the sialylation of therapeutic glycoproteins: the potential of the sialic acid biosynthetic pathway.” J Pharm Sci. 2009 Oct;98(10):3499-508. doi: 10.1002/jps.21684.  []
  3. R. T. Almaraz, et. al., “Metabolic Flux Increases Glycoprotein Sialylation: Implications for Cell Adhesion and Cancer Metastasis.” Mol Cell Proteomics. 2012 July; 11(7): M112.017558. Published online 2012 March 28. doi:  10.1074/mcp.M112.017558 []


Nasal congestion and fiber; a glycocalyx clarification

In a previous post, Glycocalyx – What’s Snot All About?

Homemade chicken soup and mucilaginous fibers would be more likely to help promote healthy nasal mucous than the fiber found in broccoli or bran cereal. Bulky vegetable and whole grain fiber is more beneficial within the gastrointestinal tract for supporting healthy bacteria but it is not typically absorbed into the blood stream.

Fiber is made up of long branching or straight chains of sugar molecules. Cellulose, a common fiber in plants, is not typically digestible by humans. Bacteria in the guts of ruminant animals like cows help breakdown the fiber contained in grasses so the nutrients become available to the animal.

The nutrients from bulky long chain fibers are broken down and used to support the growth of the gut microbes rather than being digested by our enzymes and absorbed into the bloodstream. However some of the nutrients from fibers that would normally be indigestible by human enzymes may become available after they are partially broken down or modified by certain types of gut microbes. Butyrate / butyric acid is an example of a fatty acid with anti-inflammatory benefits that can be produced by certain types of bacteria from fiber that would be indigestible without the help of the bacteria. [1] The addition of a probiotic strain of bacteria, Lactobacillus rhamnosus GG, to infant formula has been found to help promote the production of butyric acid for infants with cow’s milk allergy and it helped reduce their level of allergic sensitivity. [11]

Having plenty of bulky fiber from foods like broccoli in addition to having plenty of water can help move everything through the GI tract at a steady rate and make constipation unlikely. Other types of mucilaginous fiber can have a laxative effect possibly by helping to attract and retain water in the bowels. [2] The word mucilaginous refers to something that contains or helps produce mucilage — that gooey stuff lining the cell membranes and the rest of the body.

Mucilaginous fibers are found in the vegetable called okra which is commonly used in Creole or Cajun gumbo type stews. The inner fiber of the slippery elm tree is also a source of mucilaginous fiber. Look for very finely ground slippery elm powder in herbal specialty stores. Slippery elm bark helped keep Revolutionary War soldiers alive during a harsh winter when they were left hungry enough to eat the inner lining of tree bark. Other settlers depended on it for food too. [3]

Marshmallow root powder [4] is similar to slippery elm powder but the marsh mallow plant is more available than slippery elm trees which may be help explain why more people have heard of marshmallows than slippery elm trees but it also might be the deliciousness of marshmallows. The sweet airy candies were originally made with marsh mallow powder. Either slippery elm powder or marshmallow root powder may help soothe sore throats or sore digestive systems when dissolved in tea or taken with some other food. I add a 1/4 to 1/2 teaspoon of slippery elm powder in a mug of herbal tea when I have a sore throat. Commercially slippery elm powder has been available in the Herbal Medicinal brand tea called Throat Coat. Marshmallow root powder is categorized as an expectorant within herbal medicine which means it may help loosen lung congestion.

Chia seeds also contain a mucilaginous fiber. Okra, slippery elm powder and chia seeds may also help prevent constipation or may help if constipation is already a problem. [2]

Chicken soup made the old fashioned way may also help loosen congestion because it acts as an anti-inflammatory agent and helps thin nasal congestion. [5] Glucosamine may be released from cartilage and bone marrow during the long slow cooking of a soup stock made with bones. [9]  Glucosamine is also the healthy type of sugar found in the tough shells of insects (chitin, [10]) and in the shells of shellfish. It has been found beneficial for reducing arthritis pain with a 1500 mg/day dose. [8]

Hot pepper also helps loosen nasal congestion but not because of mucilaginous fiber. The capsaicin content of hot peppers reduces nasal congestion by activating vanilloid receptors. Capsaicin is now available in a nasal spray for non-allergic rhinitis. It may be helping to desensitize overactive vanilloid receptors for some people. [6, 7]

Adequate fluid and sodium and other electrolytes are also important for a healthy glycocalyx. It is a protective layer where white blood cells patrol for pathogens and the sticky mucous helps collect dust and other debris and move it out of the lungs and nasal passages. The glycocalyx layer coating our GI tract may also help prevent allergens from entering the blood stream and add strength to the delicate layer of cells and tight junctions that make up the walls of intestines. A fiber rich diet not only feeds the good guy bacteria, it may also help prevent food allergies by strengthening the intestinal walls.

The branching water soluble mucilaginous fibers weave together and form an intricate network that might look semi solid but is really mostly water — like a gelatin dessert. The structure can be unstable however and dissolve easily in the presence of excess acidity or salt. So my self care treat when I’m feeling very congested is a trip to a restaurant for a bowl of Hot and Sour Soup. It has the capsaicin from hot pepper and the anti-inflammatory power of chicken broth and garlic and it also provides fiber and other nutrients from the two types of mushrooms, straw mushrooms and black fungus, and the baby sweet corn, bamboo shoots, and water_chestnuts.

This post is part of a series on the glycocalyx:

  • Food Additives, leaky intestinal membranes, and autoimmune disease
  • Fringe Report: The glycocalyx, fiber rich produce, and intestinal health, 
  • Transport across the glycocalyx; a link
  • Glycocalyx – What’s Snot All About?

/Disclosure: This information is provided for educational purposes within the guidelines of fair use. While I am a Registered Dietitian this information is not intended to provide individual health guidance. Please see a health professional for individual health care purposes./


  1. Butyric acid-producing anaerobic bacteria as a novel probiotic treatment approach for inflammatory bowel disease. [1]
  2. Michael Ravensthorpe, Three mucilaginous foods that make great natural laxatives, July 18, 2014, [2]
  3. By Victor A. Croley, Slippery Elm Uses: Learn the benefits of Slippery Elm trees, including how to use it as a natural health remedy., January/February 1977, [3]
  4. Marshmallow Root Powder [4]
  5. Mayo Clinic Staff, Chicken soup: Can it cure a cold? [5]
  6. Alisha Mehta, Chili Peppers and Nasal Congestion, Nov. 8, 2011, [6]
  7. Umesh SinghJonathan A. Bernstein, Intranasal Capsaicin in Management of Nonallergic (Vasomotor) Rhinitis., Capsaicin as a Therapeutic MoleculeVolume 68 of the series Progress in Drug Research pp 147-170 [7]
  8. WebMD, Supplement Guide: Glucosamine [8]
  9., Benefits of Bone Broth, [9]
  10., Chitin, [10]
  11. Roberto Berni Canani, et. al., Lactobacillus rhamnosus GG-supplemented formula expands butyrate-producing bacterial strains in food allergic infantsThe ISME Journal advance online publication, 22 September 2015; doi:10.1038/ismej.2015.151 [11]
  12. Fiber Consumption Increases Beneficial Bacteria in the Gut Microbiome, 8/20/2015, [12]
  13. Oh B, et. al., The Effect of Probiotics on Gut Microbiota during the Helicobacter pylori Eradication: Randomized Controlled Trial. Helicobacter. 2015 Sep 23. doi: 10.1111/hel.12270 [13]

Glycocalyx – What’s Snot All About?

*This post was written in 2010 as the second chapter of a book that I had started writing about nutrition and my own struggles with health. I’ve shared other sections from the book but I had never shared the following chapter because of the taboo nature of nasal mucous — common sense suggested that it is just too controversial a topic to write about nasal congestion — but snot’s all right, we need it to help stabilize the thin layers of membranous cell walls that surround all of our cells and organs.

“Good behavior is attained at a young age.”                            – Burkino Faso proverb

[1, African wisdom desk calendars, Annetta Miller]

Is picking it and eating it a disgusting and filthy habit or an oral vaccination boost to the immune system? Traditional Eskimo cultures conserved fluid and heat by picking and eating it. [3]

Just what is snot? It may be described as a freeform gelatinous matrix of glycolipids and glycoproteins that covers our internal surfaces and is known as the glycocalyx.

Good snot, bad snot, it’s not all the same. Healthy mucous layers are two millimeters thick — about the same width as a piece of thread or single strand of hair. Obviously we can produce a lot more than that in response to sickness or allergies. Over the course of my life I have had a lot of experience with nasal mucous and congestion. Most of my childhood was spent breathing through my mouth because I was so congested, so often. On a good day I would be able to breath through one or the other nostril but usually both were congested – and messy. Eventually I learned how to tell whether I needed antibiotics or more antihistamine based on the color, texture, and smell of my nasal mucous.

Gross yellowish-green mucous that had a rotten smell and a stringy, sticky texture meant go to the doctor and get antibiotics because the congestion has become a lung infection.

Thin, watery, clear or whitish mucous is produced in large amounts during allergy attacks. Mucous produced due to allergies didn’t have smell associated with it in my experience. The thin fluid mucous produced in such large amounts during allergies may be helping the body carry the allergen debris up and out of the lungs. Constantly suppressing this response with medications may produce short term symptom relief, however in the long run using medications that dry up mucous may be allowing the allergens full access to deeper lung tissue made accessible through the artificially opened airways. The mucous is part of our body’s defense system.

Coughing and sneezing and moving the mucous out may be better for your health than regularly using an over the counter medication. Cleaning up the environment and removing dust and allergens would also probably be better for your health, when possible, ie: you can stop smoking but you have little control over smog alert days beyond wearing a face mask and voting for environmental protection; or you can vacuum and wash your bedding weekly but you may not be able to give away the family pet as easily.

I tried a nasal steroid spray for the first time recently and discovered myself producing a brand new type of mucous. My airways felt more open than usual but I also developed a new cough that felt like I had something stuck in my throat that I was choking on, like a cat with a hairball. When I successfully cleared the mucous, it appeared a typical whitish color but the texture was much stickier and slimier — more like my childhood toy can of Slime. I stopped using the steroid nasal spray fairly quickly; free flowing snot’s all right — sticky, slimy snot is not — it isn’t able to be expelled as easily. Free flowing mucous allows the body to carry allergens and pathogens up and out of the lungs when the mucous is thin enough to allow productive coughing.

Occasionally I would blow my nose and find little round globule of clear semi-solid mucous — fascinating for an easily amused and not easily disgusted child — they looked just like a gelatin dessert without the bright food coloring. The chemical structure of mucous is similar to a gelatin dessert or fruit jams and jelly. Fruit jams and jelly thickens when the pectin fiber is cooked. Heating the pectin fibers cause them to change shape and form the semi-solid structure of the jam or jelly. Gelatinous mixtures are all fairly chemically unstable and minor changes in acidity or hydration may cause changes in the structure or cause the gelatinous mixture to dissolve back into a fluid.

Chemical mixtures are made when we cook food. Tiny chemical changes can produce big changes in a “free-form gelatinous matrix.” You could experiment by adding a little lemon juice or carbonated beverage to a bowl of a gelatinous dessert or scoop of jam. The acidity should cause the gelatinous structure to break apart and get watery looking again.

The glycocalyx may act a little like glue between cells or like a sealant coating pipes in a plumbing repair. The jelly-like glycocalyx helps protect our inner surfaces around cells and in the lining of blood vessels and throughout the intestinal tract. A healthy glycocalyx layer may help prevent allergens from leaking through the intestinal lining into the bloodstream. Pectin is important for making jam or jelly and eating fiber rich foods everyday is probably just as important for maintaining a healthy glycocalyx. Good sources of fiber include any whole plant foods such as: vegetables, fruits, mushrooms, whole grains, beans, nuts and seeds, and herbs and spices. There is also a healthy type of fiber in edible insects called chitin.

Happy dining!

— on fiber rich foods of course.     😉

Read more about which types of fiber are beneficial within the GI tract and which types of foods and fiber might help with nasal congestion:  Nasal congestion and fiber; a glycocalyx clarification


A gelatin dessert.

*Having enough water every day is also important for healthy mucous. And the electrically active minerals sodium, potassium, calcium, and magnesium are also important in fluid balance and healthy mucous .

Read more: Electrolytes are essential, magnesium helps protect brain cells 

/Disclosure: This information is provided for educational purposes within the guidelines of fair use. While I am a Registered Dietitian this information is not intended to provide individual health guidance. Please see a health professional for individual health care purposes./






Bioslime is another word that is used specifically to describe the gelatinous glycocalyx layer produced by pathogens on the surfaces of transplant devices and tubing used in patient’s wounds for drainage or tube feedings.