October 2025

Immune Resilience

• Ecological Immunity
• Snot – Your Immune System Superpower
• Rethinking Fever Beyond Suppressants
• Immune Resilience – Practical Tips

Between the fall equinox and winter solstice, we see a rapid increase in colds, flu, and COVID cases. However, not everybody get sick, some people with a resilent immune system never “catch” a cold even if everybody around them is sick. What is their secret?

Snot – Your Immune System Superpower

Produced by the mucus membrane, mucus is found in all the hollow organs in the body:

• The digestive tract from mouth to tail.
• The respiratory tract, in the nose, trachea, and lungs.
• In the kidneys and bladder
• And in the reproductive system

As you might guess from how mucus is spread all over the body, it has some crucial functions.

The functions of mucus in your body.

Mucus has four crucial functions in your body. It lubricates, protects, traps, and feeds.

Lubricate

Like honey on a toast, a thick layer of mucus is spread over the epithelium of all the hollow organs in your body. The epithelium is your inner skin, a layer of cells that comes in direct contact with the food you eat and the air you breathe.

In some places, mucus protects the epithelium from substances the body produces. For example, the PH in your stomach is very low, 1.5-3.5. The acidic environment in the stomach is crucial for breaking down proteins to amino acids and extracting B vitamins. However, stomach acids may harm the epithelium, causing burns, DNA changes, and even cancer if a heavy layer of mucus does not protect the stomach.

Trap and expel

Mucus viscousity means that it traps pathogens right as they enter your body in the nose, mouth, throat, and lungs. Once these pathogens are trapped, the mucus will initiate an “expel response”, coughing, sneezing, or dripping.

When the body senses an increase in pathogen exposure, such as environmental allergens, viruses, or bacteria, it will increase mucus production to get rid of the invaders.

The solution modern medicine has to offer is drying the mucus with antihistamines, which is exactly opposite of what the body is trying to do.

Protect

Mucus is much more than water and salt; instead, it contains important immune cells that are the frontline of your immune system.

• Immunoglobulin A (IgA) is the most abundant antibody in the body. It prevents pathogens from binding to the cells of the mucus membranes and works with mucus to trap and expel them.
• Lysozyme is an antibacterial enzyme found in tears, saliva, nasal cavities, and the digestive tract. It destroys bacteria before they can penetrate deeper tissues. To produce lysozomes, you need zinc. Inflammation makes it hard for your body to produce lysosomes.
• Lactoferrin is an immune binding glycoprotein. It binds to iron, hence starving invading bacteria. Our resident bacteria developed adaptive strategies for living in a low iron environment, which means that only pathogenic bacteria are affected by lactoferrin, hoarding all the iron.
• Lactoperxide is an enzyme that releases antimicrobial compounds that are effective against bacteria, viruses, and fungi. It directly destroys their cell membranes and injects them with toxins.

Feed

Your residential bacteria, these critters that live in and on your body, signed a contract with humanity some six million years ago. They boost and support your immunity, increase energy and mood, and in exchange, you provide room and board.

The microbiome loves to munch on your mucus, which triggers the mucus membrane to produce fresh, vital mucus.

Mucus production, microbiome, and immunity rely on each other. In the absence of a prolific, balanced microbiome, both mucus production and immunity will be compromised. However, not enough mucus means a starving microbiome.

How to read your mucus?

The color of your mucus tells a story about the type of immune cells that live in your mucus.

Clear/White Mucus:

• Normal baseline – healthy mucus production
• Viral infections – early stages before bacterial involvement
• Allergic reactions – histamine-driven increased production
• Good hydration and healthy mucin production

Yellow Mucus:

• Neutrophil infiltration – white blood cells fighting infection
• Early bacterial involvement – immune cells releasing enzymes
• Transition phase – infection progressing from viral to bacterial

Green Mucus:

• Active bacterial infection – high neutrophil count with myeloperoxidase enzyme
• Chronic sinusitis – ongoing bacterial colonization

Brown/Rust Colored:

• Blood breakdown products – old hemoglobin degradation
• Chronic bleeding from damaged mucosa
• Environmental particles – especially in the respiratory tract

Pink/Red Streaked:

• Active bleeding – fresh blood from irritated or damaged tissue
• Severe inflammation with capillary fragility
• Trauma to mucosal surfaces

How to support a healthy mucus?

Now that I have convinced you of the crucial role of mucus for increasing your immune resiliance, you want to support your body’s innate capacity to build mucus.

Practical strategies:

Mucus production is labor intense and energy consuming task. The first way to support a healthy mucus production is to ensure that the mucus membrane cells have all the nutrients they need to produce energy. These nutrients are vitamins B1, B2,B3, and B5, magnesium, and iron.

Manage your stress. Under stress, your autonomic nervous system shifts from parasympathetic (rest and digest) to sympathetic (fight, flight, freeze)response. Mucus membranes are not a priority when the body experiences a threat to its safety. The body will shuttle nutrients, oxygen, and iron to the brain, hands, and legs to allow you to fight or flee. Meanwhile, your mucus membrane will be starving.

Add prebiotics and probiotics to your plate. Prebiotics like fiber will feed your existing biome, increasing numbers and variety. Probiotics from fermented foods can increase the resilience of microbiome colonies. Overall, a thriving microbiome encourages mucus production.

When you are exposed to allergens or pathogens, you produce excessive mucus. Your mucus will also become denser because it contains more immune cells and pathogens. The first tendency is to get rid of the mucus.

But what if?

Instead of drying the mucus, you promote more mucus production, making it thinner, lighter, and easier to expel, as well as all the pathogens and waste products associated with the invasion.

What do herbs have to offer us?

Plant mucus

Plant mucus, called mucilage, is primarily made from carbohydrates (complex sugars) and protein. In plants, mucilage stores fluids either for the plants themselves or for seeds while they are germinating. Plants also use mucilage as a physical barrier to protect themselves from microbes and heal wounds, as in the pitch of pine trees.

Demulcent herbs contain mucillants. Some demulcents to think of:

Marshmallow

Marshmallow is one of the most used herbs for its mucilants. The root is much more slimy than the leaves and flowers. A powder of the root added to soup or smoothie can thicken them.

For people who gag when trying to ingest the slime of marshmallow root, you can use the flowers and leaves. They are slightly sweet and moist and make a great addition to tea.

Marshmallow is easy to grow and a beautiful addition to the garden.

Slippery elm

I never used slippery elm. Most American Elms died due to a disease. I actively avoid using slippery elm medicine to protect the species.

Plantain

Plantain is a common weed found in everybody’s backyard. If you don’t spray your lawn, you can harvest your plantain and add it to your infusion.

Plaintain is anti-inflammatory, which makes it useful in mucous membrane inflammatory conditions.

Violet

A gentle mucilant that is also lymphatic. It will help move lymph fluids, mobilize immune cells, and remove waste products. Violets are a beautiful, cheerful addition to any garden.

Solomon Seal

Solomon Seal root is a mucilaginous herb with a special affinity to the musculoskeletal system, for dry, creaky joints.

These are just my favorite demulcent herbs. I encourage you to find the ones that appeal to you.

Demulcent herbs are best used in tea. Steep them in room temperature water for a couple of hours before drinking.