Microbiome and gut health
how to supercharge imunity
Information provided below is meant for educational purposes only, and does not constitute medical or nutritional advice or act as a substitute for seeking such advice from a qualified health professional. 


You may have some questions now.

Why do some of us get sick more often than the others? What makes some people more susceptible to get sick? Is it possible to, by supporting your immune system, become almost resistant to colds, flu and other infections? And if you do catch something, can you bounce back to feeling well within 1-2 days?

There are many factors that influence the condition of our immune system, some of them are genetically determined and some are determined by our environment, lifestyle, diet (the so-called epigenetics). So by and large, we can take actions to support our immunity.

Lifestyle factors that compromise our immune system in adulthood include poor diet (resulting in a suboptimal nutritional status), chronic stress (physical and psychological), sleep disturbances, alcohol overuse, cigarette smoke, pollution, prolonged and excessive exercise.

As I am writing this blog, we are facing a coronavirus COVID-19 pandemic. Catching a coronavirus may manifest from mild to severe symptoms (severe especially in elderly and those with health issues). What determines how you experience an infection is the virulence (pathogenicity) of a given virus, bacteria and the efficiency of your immune system.

“Compromised immune function increases the risk of infection”

The immune system evolved as a defense mechanism against infectious disease. The immune system is a collection of various cells and molecules present in our bloodstream, tissues and organs.  They defend our body against foreign bodies (antigens), such as bacteria, viruses and cancerous cells. There are many molecules involved in an immune response, such as lymphocytes, antibodies, dendritic cells, mast cells, macrophages, NK cells.

 It’s important to realize that to support your immune system and to have long-term results, it’s not something you do overnight, it’s a process. The more you do to positively stimulate your immunity (like eating healthy foods and having restorative sleep) and the less you do to undermine it (like eating junk foods, excess sugar, or having poor sleep), the stronger your immune system will be. In addition to building immune resilience, you can also improve, and even reverse, many health issues.

Below I have put together essential and powerful tips to make your immune system resilient. It’s all about having a good foundation. There is NO shortcut or a miracle pill and the reality is that the safest, most robust interventions include lifestyle interventions. It's worth the daily investments in your diet and lifestyle.


Get quality sleep. Sleep is one of the best immune superpowers. Sleep deficit promotes release of pro-inflammatory cytokines (more inflammation) and can lead to chronic, systemic low-grade inflammation. Studies show that sleep deprived people (common among parents of young children) are more prone to catch a flu virus, and when sick they have more symptoms and longer recovery than people who sleep well and enough. During sleep you make a hormone, a powerful anti-oxidant, melatonin. Preliminary findings indicate that melatonin could be helpful in the management of COVID-19 infections. Also, no surprise why we need more sleep when we are sick, it helps us to mobilize our immune defences. Tip: invest in a relaxing evening routine (taking Epsom salt bath, reading a book) to promote quality sleep, avoid alcohol and caffeine in the afternoon. 

Nourish your body and feed your good gut microbes.  Healthy immune system components need good and regular nourishment. Scientists have long recognized that people who live in poverty and are malnourished are more vulnerable to infectious diseases. Healthy foods provide us with nutrients and help our beneficial gut microbes (microbiota) thrive, on the contrary junk foods and sugary foods deprive us from nutrients and result in compromised microbiota. Gut microbes teach our immune system to generate appropriate immune response and competes with pathogens for nutrients. Gut health is essential to immune health and how we respond to viruses and other pathogens. Therefore, the quality (not quantity) of foods you eat is essential. Research indicates that brightly colored vegetables and fruits boost immunity better than most supplements. Tip: have a diversity of healthy foods, strive for colors and quality. Eat high amounts of vegetables and fruits, have healthy fats and adequate protein. Avoid sugar, alcohol and processed foods.

Minimize stress. Scientists are actively studying the relationship between stress and immune function and there is still a lot to learn as stress is perceptive and difficult to define. But what we know now is that short-term stress can actually boost your immunity and is adaptive, however chronic stress is maladaptive, it weakens our immune system and can result in Th2 dominance (Th2 cells are helper T cells producing various interleukins) resulting in an immunological shift, imbalance. When we’re stressed, the immune system’s ability to fight off antigens is reduced. That is why we are more susceptible to infections. For example, prolonged stress and elevated cortisol levels can suppress the effectiveness of the immune system (lowers lymphocytes). Luckily, humans have the capability to modify what they perceive as stressful and how they respond to it. It’s all in our hands, whether we manage stress or stress manages us. Tip: some successful stress management strategies include meditation, mindfulness, psychotherapy, physical activities, social connection, breathing, hobbies, humor, keeping a perspective in life. Do what works for you.

Stay hydrated. Proper hydration helps us to feel better, to function better and it’s key to our overall health. Water is our building block, solvent, lubricant, medium for biochemical reactions, transport medium, thermo-regulator, and shock absorber. Water facilitates countless number of processes in our body so if we have too little of it, these processes will be impaired, impaired at the cellular level. If you are chronically dehydrated, at some point you may start experiencing certain symptoms like constipation, headaches, or dryness. Your optimal water intake is affected by physical activity, exercise, metabolism, diet, health status, humidity and ambient temperature. If you sport and sweat you obviously need to drink more water. Tip: the average recommendation for adult females is about 2,5 liter daily, for adult males about 3-3,5 liter daily.

Exercise moderately. Regular physical activity of moderate intensity is one of the pillars of healthy living. It improves cardiovascular health, helps control body weight, and protects against a variety of diseases. Just like a healthy diet, exercise can contribute to general good health and therefore to a healthy immune system. Exercise, by promoting good circulation, can allow the cells and immune system molecules to move through the body freely and do their job efficiently, and therefore be helpful in reducing inflammation, maintaining the proper immune response, enhancing immunosurveillance, and reducing psychological stress.

Be positive. Your mindset influences not only how you perceive the world but also how you feel and how your immune system is working. Positive thinking creates positive results and more optimistic individuals are less likely to suffer from chronic diseases and stress burden. Also, being surrounded by loving and positive people helps us to stay positive. Tip: by telling yourself “I am strong”, “I am healthy”, “I am resilient”, “I have a supercharged immune system” you are telling yourself how you should feel. It literally can make you feel better. And it’s not about curing a disease by positive thinking but about creating health promoting thoughts in contrast to disease promoting thought (“I am weak”, “I am sick”). You can “program” yourself to a certain degree. Your mind believes what you are saying, whether it’s good or bad. So let’s keep it positive.


Micronutrient (vitamins, minerals) deficiencies can impair immune function. Therefore, malnourished individuals are more prone to infections and may have a more challenging time to recover. Micronutrients with most vital immune support include vitamins C and D and zinc. Also, vitamin A, B12, B6, E, folate, selenium, iron, and copper are essential to ensure the proper integrity of immune barriers and proper function of immune cells. These micronutrients are involved at every stage, via various mechanisms, of the immune response. Noteworthy, foods contain many nutrients we can never get in supplements, yet foods alone will not always meet all of our needs for micronutrients. Thus, sometimes micronutrient supplementation is beneficial to support immune function and/or reduce the risk of infection.

A word of caution about supplementation, more supplements or higher dosages do not necessairly create better results, on the contrary - over dosing can even create unwanted results! It is about having enough of what our body needs. Micronutrients can challenge your immune system when you have too little and too much. They are also not helpful if they are in the wrong chemical form or in poor proportions. For example, there is a tendency to take very high amounts of vitamin D3 without any assessment of a baseline vitamin D levels. I discourage taking mega doses of any individual vitamin or mineral, unless recommended by a health care professional.

 You may consider taking daily:

  • A high-quality Multi-Vitamin & Mineral Supplement
  • A high-quality omega-3 supplement (DHA, EPA), especially for individuals with a low intake of fatty fish

In a period of an increased infection risk and/or lower immunity:

  • Zinc - 15-45 mg daily (zinc glycinate, zinc methionine, zinc gluconate, zinc citrate or zinc sulfate), best divided in 3-4 doses taken through the day. If you supplement with zinc daily for a longer period of time, take copper supplement as well. Aim to get 1-3 milligrams of copper per day. Aim for 15-to-1 zinc to copper ratio to provide 1 milligram of copper per 15 mg of zinc.
  • Vitamin D: 1,000 – 5,000 IU daily (in case of a deficiency the dosage might be adjusted). Of note, sunshine is where most of our vitamin D comes from. Resonable sun exposure can elevate your vitamin D levels without a need of supplementation. 
  • Vitamin A: 3,000 - 10,000 IU daily (in case of a deficiency the dosage might be adjusted)
  • Vitamin C (with bioflavonoids): 500 - 3,000 mg daily
  • Elderberry extract: 500 - 2,000 mg daily
  • Echinacea extract: 500 - 2,000 mg daily

I do not recommend supplementation with high doses of individual vitamins and minerals for a longer period of time. 

Other immunomodulating compounds: Astragalus, medicianal mushrooms (like Reishi, Turkey Tail), antioxidants (like glutathione, resveratrol, flavonoids, vitamin E, selenium, melatonin, quercetin)


In addition to what’s mentioned above, there are few measures specific for the COVID-19 situation, such as:

#1 Avoid exposure. The key is prevention. One of the best strategies is to isolate to prevent contracting a virus. People can be contagious days before they have any symptoms at all. If you have any possible options for staying away from all others, please do so. Avoid touching your eyes, nose, and mouth.

#2 Realize it’s temporal. There is panic and stress around coronavirus situation, but it’s important to realize that it will pass. You need to use your mind to stay calm and remind yourself that it’s a temporal situation.

#3 Wash your hands well and regularly, disinfect and clean surfaces.

#4 Cover your mouth when coughing.

#3 Include following herbs, extracts and foods in your diet for protection: oregano, turmeric, ginger, citrus peel, tickberry leaves, orange peel, garlic (stabilized allicin), onion, green tea, wild berries, pomegranates, seaweeds, mushrooms, cat's claw tea, lemon balm tea, elderberry, and grapefruit seed extract.

#5 Sore throats: Try salt water gargles, sage tea gargles, hot teas and lozenges containing slippery elm, lozenges with zinc for fighting infection and soothing irritated sore throats.

#6 Respiratory congestion & congested sinuses. Nasal irrigation using a neti pot (with saline solution) can be very helpful, as well as nasal sprays (with saline solution, xylitol) and sinus drainage massage. Saline solution (water + salt) is easy to make or can be purchased. You can also use a humidifier, vaporizers, or steam inhalers, or spend time in steamy baths or showers. Vaporizers and inhalers can also be used with decongestants or essential oils such as eucalyptus, menthol, peppermint, or frankincense.

#4 Be careful with anti-inflammatory medications like Ibuprofen and Aspirin. It's unclear at the moment but there was a suspicion that they may raise the risk of COVID-19 complications.

#6 Be careful with high doses of vitamin D3 and vitamin A. Vitamins A and D are very important to ensure a proper function of our immune system. However, there is a hypothesis that over-supplementing with these vitamins may potentially make us more vulnerable to COVID-19 infection. Why? Because the coronavirus uses the receptor ACE2 (angiotensin-converting enzyme 2), mainly in the respiratory tract, to get inside our cells. And these two vitamins are helping us to make ACE2 and therefore it’s thought that possibly the more ACE2, the higher risk of virus invasion.

We are still learning about the impact and the best management of COVID-19, therefore the recommendations can change overtime as new research emerges.

Last but not least, if you are feeling unwell, watch out for the typical symptoms associated with the COVID-19 infection. Most of those who contract COVID-19 will have less or more severe symptoms. While having no symptoms is possible, if you have COVID-19 you are likely to experience: fever, cough, impaired breathing, fatigue and a small population of patients may have gastrointestinal complaints like diarrhea.

Category: Microbiome and gut health icon March 19 2020
Dr Joanna Krzeslak-Hoogland
Author: Dr Joanna Krzeslak-Hoogland

Being inspired by the effect of nutrition, lifestyle and mind on our health, I am dedicated to help people on their journey to wellbeing.

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