10 ways to boost your immune system naturally

When asking people about their “tricks” to boost immunity before winter, you usually hear things like:

• Washing hands a lot
• Eating lots of fruits, especially citrus fruits, kiwi etc. for vitamin C
• Eating garlic and onions
• Taking supplement X or Y
• …

If we consider that 70-80% of our immune system lies in the gut, it is interesting that improving gut health is usually not mentioned. Yet, without a healthy gut, none of the above means will keep you from getting sick. Worse actually: Some of them might even be counterproductive to the effort of establishing a healthy gut flora, like eating lots of sugary fruits, that on top cool down your body (not exactly what you need in winter). And even the best supplements in the world won’t be well absorbed by a permeable or leaky gut.

So let’s talk about gut health as THE important factor to not only get through winter without catching the flu, but to improve your overall health and well-being all year long.

There are two main aspects to gut health: gut flora and gut permeability that are interdependent.

Gut flora

The gut is colonized with billions of bacteria, which make up the so-called gut flora. Just like in nature there are desirable and less desirable organisms. In a healthy body (ecosystem) everybody has their role to play, there is balance and the “good” guys keep the “bad” ones under control. “Bad” bacteria, yeast, fungi or parasites – just like weeds – only become an issue when they overgrow. This happens when the body is not well nourished or weakened through internal or external stress (see chapter on sources of stress) or if there is not enough diversity in our gut flora, i.e. through restrictive diets. A vicious cycle is then started, because the pathogens make you crave what they need to survive: sugar, bread, fermented substances… further disturbing the gut flora. This imbalanced gut flora then plays a major role in damaging the gut lining (leaky gut) and nutrient malabsorption.

Gut permeability

A healthy gut lining is tight, meaning that the villi (“fingers” sitting on the gut wall) only absorb nutrients made available through digestion, but do not let particles of undigested food, yeasts, parasites, environmental toxins or other potentially pathogenic elements pass through the gut wall into the blood stream. If that happens, an immune reaction is caused to fight the intruder. This is an inflammatory stress reaction which – if continuously triggered – wrecks down the immune system over time, increases the risk of developing allergies, skin issues, respiratory issues, joint pains, thyroid disorders, auto-immune or degenerative diseases and also impacts your fertility.

Since there is a direct connection between the gut and the brain, a leaky gut is also associated with an impaired brain barrier, allowing toxic elements to “leak” into the brain and potentially cause brain fog, concentration and memory loss, depression and/or behavioral issues (e.g. ADHD in children).

The overgrowth of bad bacteria, parasites, yeasts (in other words, an unhealthy gut flora) plays a major role in damaging gut lining.

This is why it is so important to keep the gut flora balanced.

Factors altering gut flora and making the gut leaky

When bad bacteria, yeasts, fungi or parasites are allowed to overgrow, we talk about gut dysbiosis. This condition can be caused or worsened by:

• Chronic stress, incl. external stress from work, relationships, money… as well as internal stress from food (see below),but also from thoughts and feelings (read more about the psychic immune system here)
• A diet high in carbohydrates, especially refined carbs, like sugar, white bread & pasta…, but also too much fruit or whole grains, especially if those are not correctly prepared). In general, sugar/carbs feeds bad bacteria and yeasts. Some studies also link gluten (contained in wheat, spelt, rye and barley) to increased gut permeability.
• A diet high in omega 6 fatty-acids (especially from cheap vegetable oils, soy and corn, but also an excess of nuts & seeds, especially if intake of omega 3 is deficient). Those are pro-inflammatory and can damage gut lining.
• A diet high in processed foods (like extruded breakfast cereals, pasteurized dairy, cookies, snacks, ready-to-eat meals, soy milk, meat replacements…). Industrial processing, especially high-heat, high-pressure or chemical processing, alters the chemical structure of foods and might render them unrecognizable and/or damaging to our digestive system – while being a welcome food for bad bacteria or yeasts.
• Food intolerances:  Having food intolerances and allergies is always an indication that the gut is permeable to some extent. The leakier the gut, the more food sensitivities you are likely to have. Continuing to eat those foods further damages the gut lining and causes an inflammatory immune reaction and release of stress hormones in the body.
• Pesticides, GMOs or additives in food, chemicals in cosmetics, or environmental toxins contained in the air or water you consume damage the gut lining.
• Lack of natural, traditional saturated fats, such as raw butter or coconut oil. Those contain anti-bacterial properties and heal the gut lining. Saturated animal fats also contain vitamins A, D, K2 and cholesterol which nourish immune-system-supporting organs / glands, repair gut lining and optimize digestion (undigested foods feed bad bacteria).
• Lack of traditional probiotic and prebiotic foods and foods supporting a healthy gut lining. Probiotic foods naturally contain “good” bacteria and digestive enzymes. Prebiotic foods act like fertilizer to those good bacteria, feeding them so they can survive and grow.
• Antibiotics, which wipe out bad AND good bacteria and damage gut lining
• Other medication, such as the “pill”, because hormonal changes influence gut flora
• Foods that push your individual Metabolic Type out of balance.

Note: Babies get their gut flora from their mother via the placenta and the birth canal. The gut flora of the mother actually influences the gut flora of up to seven generations to come! Thus, it is essential that especially women take good care of their gut prior to conception. If the child has been or has to be delivered via C-Section, this means that instead of being exposed to bacteria of the vagina, the baby got or will get exposed to bacteria of the skin, the air and the environment in general. It is especially important to help balance this child’s gut flora through (infant) probiotics and an anti-inflammatory diet. Babies are born with leaky guts. This is why it is important to NOT feed baby any foods that it cannot yet digest, especially grains and cereals, before the gut closes at around 3 years of age. Otherwise they might be at a higher risk for food sensitivities and an overall impaired immune system. Especially if your child has issues with skin or allergies or is considered “problematic”, it is a good idea to focus on improving gut health.

How to re-establish a healthy gut

Healing the gut consists of two strategies: Removing physical, emotional, mental and even spiritual stressors and blocking factors AND introducing gut healing foods, substances and supportive habits and factors.

Apart from avoiding the foods mentioned above (esp. refined carbs and processed foods) and limiting stress, it is crucial to consume foods feeding beneficial bacteria and the gut lining:

1. Home-made bone broth

Home-made bone broth is rich in gelatin, healthy fats (esp. beef stock, chicken fat is less favorable since it contains more omega 6), certain essential amino-acids and minerals. 

Making broth from a whole chicken, chicken drumsticks/legs, beef or venison bones is really easy, not expensive and not overly time-consuming. Get the recipe here. If your broth doesn’t gel (e.g. if you use only marrow bones), you can “cheat” and add some powdered gelatin from grass-fed, antibiotic & hormone-free cows (available at www.ergomax.nl).

You can also get a really good, ready-to-eat bone broth here (click). Or maybe fancy a protein powder made from real broth?

Note that store-bought bouillon “cubes” do not contain any health-promoting properties. but are usually full of cheap salt and additives.

2. Animal foods rich in saturated fats, cholesterol and vitamins A, D and K2

It might seem like irony to you that the very foods demonized for years are crucial for a healthy immune system. Saturated animal fats, which are largely present in raw butter, cream, cheese, egg yolks, organ meats, greasy meats, lard etc. are antimicrobial and together with cholesterol they help seal and heal the gut lining.  Vitamin A, D and K2 – exclusively contained in the fats of free-range, pasture-raised animals (in their “real”, easily absorbable form), are crucial for immunity, nutrient absorption and balancing hormones. This is why raw cod liver oil is such a great immune booster.

When it comes to dairy, prefer cultured dairy, such as yogurt or kefir. It contains less sugar and more beneficial bacteria. You might want to limit dairy in winter due to its tendency to cool the body.

3. Probiotic foods

Probiotic foods are naturally rich in beneficial bacteria, vitamins & minerals and digestive enzymes.

• RAW (= uncooked) sauerkraut (or other lacto-fermented vegetables). Find the recipe here.
• Traditionally prepared pickles or Kimchi (not the vinegar version you can find in stores),
• Kombucha (again – the home-made version and not the sugary version you can find in stores)
• Kefir (ideally from raw milk)
• Natural yogurt or cheese made from raw milk

Eat these foods every day in small quantities as a complement to meals.

Note: The more messed up your gut, the less you might tolerate probiotic foods. Rather than omitting them completely though, start very, very slowly, i.e. with a single string of sauerkraut. In addition to that, you might want to add a high quality probiotic supplement to your diet (I recommend Prescript Assist available here. This product combines pro- and prebiotics).

Combining probiotics with prebiotics is especially powerful and recommended.

4. Pre-biotic foods:

If probiotics are like seeds, prebiotics are like fertilizer – the food for those bacteria. This is where the onion and garlic come into play. Prebiotics consist of soluble fiber. Contrary to insoluble fiber its purpose is not to create more bulk in your gut, but to keep your gut bacteria healthy and happy. If they are happy, you are happy because the substances created as by-products of their digestion (fermentation) such as certain short-chain fatty acids, are highly beneficial for your own health, immunity and fertility. Some food sources of pre-biotics:

• Jerusalem Artichoke (topinambour) – not to be confused with regular artichokes
• Black salsify (scorsoneres)
• Legumes (such as lentils or beans), properly prepared
• Garlic & Onions 
• Foods containing “resistant starch”. Potatoes or rice that have been cooked, cooled down and re-heated (not more than 42 degrees Celsius) transform some of the sugar into resistant starch
• Raw potato (in very small quantities and without any toxic green parts)
• Plantains (the starchy bananas used for cooking)

Attention: the more messed up your gut, the more digestive discomfort, such as bloating, gas etc. prebiotics will cause you. Rather than omitting them completely, introduce them very, very slowly, i.e. 1/4 teaspoon and slowly build up.

Summary: 10 ways to boost your immunity naturally

1. Avoid all foods feeding bad bacteria, basically foods high in sugars, processed foods and foods you can’t digest / are intolerant to. Buy organic whenever possible.
2. Prepare your own bone broth once a week and consume it daily – either pure or as a basis for soups or sauces or to cook your (correctly prepared) grains or pulses in it. In addition to that, add powdered gelatin to smoothies, soups and baked goods.
3. Don’t be afraid of saturated fat & cholesterol contained in foods from free-range, pasture-raised animals. Prefer natural, traditional raw butter or ghee over vegetable oils.
4. Take extra virgin cod liver oil for a supply of natural vitamin D and A (synergistic effects – much better than isolated, synthetic vitamin D). Alternatively take drops combining vitamin D3+K2.
5. Eat plenty of vegetables, but only little fruit. Always combine with fats/proteins.
6. Prefer foods that are good or neutral for your individual Metabolic Type.
7. Eat probiotic and pre-biotic foods on a daily basis, ideally with every meal (start with small quantities and build up gradually to avoid bloating). Optionally take a good pro & prebiotic supplement as well. I recommend Prescript Assist for adults and GutPro Infant for children up to 2 years.
8. Limit stress and take your time for eating and chewing. You can eat the healthiest and highest quality foods in the world – if you are not able to digest well, they will not do you any good. You are NOT what you eat, but what you can digest!
9. Avoid all unnecessary medication, incl. the pill. If you have to take antibiotics, make sure to re-build your gut flora by taking a probiotic supplement, in addition to eating probiotic foods.
10. Lead a healthy lifestyle in general, getting enough rest, fresh air and body movement.

And as a bonus: Develop a strong PSYCHIC immune system. Learn more about that here