Until the year 2020, immunity-boosting foods and supplements were restricted to recovery after episodes of being unwell. Most people did not pay attention to these boosters and hardly ever felt the need to do so.

But it all changed. Suddenly, immunity-boosting foods and supplements caught the centre stage and were the most sought after. People began tailoring their diets to make them nutrition-rich and also began loading up on multi-vitamins supplements.

But do these supplements and immunity-boosting food really help our body against catching viruses?

To understand this better let us first look at better understanding our immune system.

Our immune system is a network of complex stages and pathways in the body that protects our body against the invasion of harmful microorganisms and diseases. It is built on the beneficial live bacteria that live in the gut. So essentially when our body is exposed to a harmful foreign body, it fights it off to protect the body.

We, humans, possess two kinds of immunity: Innate and Adaptive.

Innate immunity is like a guarding army that stands in the first line to defend our body from the pathogens that try to enter our bodies. These protective barriers include:

Skin
Mucus
Stomach acid
Enzymes in our sweat and tears forming an anti-bacterial compound that
Immune system cells

Adaptive or acquired immunity is the kind of immunity that our system learns to recognise as a pathogen. This adaptive or acquired immunity response is regulated by cells and organs in the body like the spleen, thymus, bone marrow and lymph nodes. When these systems identify a foreign object in the body, they create antibodies and multiply the immune cells that help in identifying the foreign substance. They then remember the foreign substance and adapt to kill it sooner the next time.

So how do immunity-boosting products make a difference in this system?

According to research published in Harvard Public Health, it is important to eat enough nutrients as a part of your diet. Eating enough nutrients ensures the healthy functioning of the cells which further promotes the healthy functioning of the immune cells. However, as it turns out, individual foods offering special protection may be quite unlikely. It is important to understand that each stage of the body's immune response depends on the presence of micronutrients in the body. This includes vitamin C, vitamin D, zinc, selenium, iron etc. These are generally found in most plant and animal-based foods.

Especially, plant-based foods help the intestinal bacteria and also help in improving the gut microbiome which is almost 85 per cent of the body's immune system. As oppose to this, animal-based diets often deplete the body's good bacteria, while also promoting inflammation. This could cause diabetes, chronic obstructive pulmonary disease cardiovascular diseases, hepatitis B, cancer, and chronic kidney diseases.

Also, diets that are lower in nutrients such as ultra-processed foods, can negatively impact the body and further impact the immune system. The Western diet — high in refined sugar and red meat, and low in vegetables and fruits — can also disturb intestinal functioning.

What is gut microbiome?

The microbiome is a centre of trillions of microbes that lives mostly in the intestine or gut which is also a place where antimicrobial production takes place. According to research, scientists have found the microbiome to play an important role in effective immune function.

This directly relates to the food we eat to the health of the microbes living in the intestine. The diet plays a large role in determining what kinds of microbes live in our intestines. When you consume a high-fibre, naturally available and plant-rich diet studies suggest that the health of the microbes improves. Additionally, certain microbes also help break down fibres into fatty acids, which also stimulate immune cell activity. Since these fibres (called prebiotics) feed the microbes also, probiotic foods contain live helpful bacteria which is essential for the gut. Hence, a diet containing both probiotic and prebiotic foods could be beneficial for gut health.

According to the Harvard School of Public Health

Probiotic foods include kefir, yoghurt with live active cultures, fermented vegetables, sauerkraut, tempeh, kombucha tea, kimchi, and miso.
Prebiotic foods include garlic, onions, leeks, asparagus, Jerusalem artichokes, dandelion greens, bananas, and seaweed. However, a more general rule is to eat a variety of fruits, vegetables, beans, and whole grains for dietary prebiotics.

Safe to say

Maintaining a healthy diet can go a long way in improving gut health and preventing deficiencies of essential nutrients. But for the people who do not have access to nutritious foods, can use supplements to ensure healthy gut activity.

Especially people who belong to the elderly group, are at the high rise as immune functions generally decline at increasing age. The number and quality of cells in the body declines, which directly influences immune function.

However, it is important to remember, that vitamins and supplements are not a substitute for a healthy and balanced diet.

Apart from this, how to ensure a healthy immune system:

Eating a balanced diet that includes fruits, vegetables, protein. It is also important to consume a lot of water, to promote the acidity levels in the gut and improve the functioning of the microbes.
Avoid smoking and alcohol consumption as this directly affects cells and lungs.
Exercise regularly to ensure that your breathing, blood flow and physical and mental health.
Regulate your sleep cycle and ensure you get at least 6-8 hours of sleep daily.
Manage stress better. Your stress levels directly affect your body activity, mainly your stomach. The physical manifestations of stress are often seen in the gut area that could lead to issues related to digestion. But if you manage stress effectively, it will promote better gut health, which will further improve immunity.

It is not necessary that some specific foods will better your immune response to diseases, and hence it is unnecessary to focus your attention on only specific kinds of foods. However, it is essential to focus on eating a wholesome meal filled with nutrition, to ensure that your gut microbiome activity is regulated to ensure a better immune response.