Immune system: everything you need to know 1

Immune system: everything you need to know

Immune system: everything you need to know

Immune system: everything you need to know

The immune system is an invisible barrier that protects our body and allows us not to get sick keeping the body’s natural defenses high. Without him we could not live long: we do not realize it but every day a daily struggle for survival takes place in our body. To guarantee it the immune system has a control network, a sort of “intelligence”, which places squadrons of artillery throughout the body, ready to launch attacks against viruses, bacteria and pathogens of all sorts.

But exactly what is the immune system? Where is it? What and how does it do it?
What is the immune system?

The immune system  is composed of a series of very important mechanisms that  defend our body from the onslaught of “external invaders”  that could compromise our health. The invaders are viruses, bacteria or other harmful substances that could permanently damage us.

We do not realize it, but every day we are subject to this type of “assault”. When the defense systems, or the immune system, react quickly, before the pathogens are able to break through, our body feels nothing.
When instead the attack is massive and our immune system does not immediately recognize the enemy pathogen, we feel a series of symptoms that indicate that our body is fighting the infection . The fever caused by the influenza virus is the example par excellence.

Viruses and bacteria: what’s the difference?

The bacteria are single-celled organisms that are able to survive and reproduce themselves in different environments, resisting to heat and extreme cold. Almost all bacteria are harmless and some even help fight cancer cells and support digestion and destruction of microbes.
The virus , unlike bacteria, can not survive without a receiver . They can only reproduce by attaching themselves to cells. In most cases, they program the cells to which they “stick” to produce other viruses. In other cases they are responsible for the transformation of normal cells into malignant or cancerous cells.

Bacterial or viral pathology

Many diseases can be either bacterial or viral in nature. This is the case for meningitis, diarrhea and pneumonia. To understand the origin of these and other pathologies it is necessary to do some analysis such as:
  • urine analysis
  • blood test to confirm the diagnosis
  • Tissue “buffer” to identify viruses and bacteria .
  • sometimes, even a tissue biopsy may be necessary.
It can be concluded that to distinguish a viral infection from a bacterial one, it is not necessary to look at either the causes or the symptoms. The best thing to do is to consult your doctor because only with specific analyzes it will be possible to distinguish them and prescribe the best treatment.

Antibiotic resistance

Treatment of bacterial infections is treated with antibiotics . 

Unfortunately bacteria adapt easily and excessive use of antibiotics increases their resistance making them ineffective.

The development and use of antibiotics, starting from the second half of the twentieth century, has revolutionized the approach to the treatment and prevention of infectious diseases and of infections previously considered incurable. However, 

the appearance of resistance to antibiotics is currently faster than the development of new molecules.

Furthermore, the appearance of pathogens resistant simultaneously to several antibiotics further reduces the possibility of effective treatment. It should be emphasized that this phenomenon often involves infections related to health care, which arise and spread within hospitals and other health facilities.
The problem of antibiotic resistance is complex as it is based on multiple factors:
  • the increased use of these drugs (including inappropriate use, such as using antibiotics to treat the flu). This 

    increases the selective pressure favoring the emergence, multiplication and diffusion of resistant strains.

  • the spread of hospital infections by antibiotic-resistant microorganisms.
  • an increase in international travel and therefore a greater diffusion of the strains.

Where is the immune system?

The ability of our body to respond to attacks by viruses, bacteria and other harmful substances is called the immune response. But what are the organs that respond to the “assaults” of pathogens?
The immune system is made up of specialized cells called immune cells . The leukocytes (or white cells) present in the blood make up a large part of the immune system. Considering that blood circulates throughout our body, it is easy to understand how even leukocytes are present everywhere.
We can thus say that the immune system can be found anywhere and everywhere in our body . There are also a number of organs where white cells are present in massive quantities such as the spleen, lymph nodes, tonsils, thymus and tissues that communicate with each other via the  lymphatic vessels .
If pathogens attack the lungs, skin and intestines, macrophages come to the rescue : a type of white blood cell present in these organs.
When we get a wound, germs can enter our body through the cut. If this happens, neutrophils , another group of white blood cells, go to the injured area to destroy the germs.

The immune response

The immune response is of two types:
  • Innate (or non-specific) immune response , or a general defense mechanism, present from birth, which acts quickly (minutes or hours) and indiscriminately against any external agent . Said with a more technical jargon, the cells possess the ability to recognize the “self” from the “non self” , that is what is part of the organism compared to what is not part of it. And it attacks him.
  • Acquired immune response (or specific or adoptive) . This develops slowly after the first encounter with a specific pathogen (within a few days), but retains a certain memory to act more quickly following further future exposures.
Immune system: everything you need to know 2

The immune system regulates itself

The immune response should only activate when necessary. Fever is caused by the immune response: but what would happen if the temperature did not drop after the virus was fought and eliminated?
The immune system has different strategies to stop an exaggerated immune reaction .
It has molecules and cells that are responsible for turning off the immune response. A cell specialized in this task is the regulatory T lymphocyte .

Immune memory

Every winter a new flu virus always arrives and in a few weeks millions of people fall victim to the flu. If we are dealing with a healthy body, in a few days, thanks to fever , our immune system defeats the virus. If, after a few months, the same viral strain were to reappear, many would not even get sick, or they would have milder symptoms.
This happens because, as we have seen, by becoming ill the first time and defeating the virus, people who have already been victims of that virus have acquired a specific immunity for that particular pathogen.
This ability is another important function of the immune system : it is in fact able to remember the pathogens that have infected us, even after decades . This ability is called immunological memory  and is the basis of vaccines.


After vaccination our body “remembers” these viruses or bacteria in a specific way. Therefore, in the event that it comes into contact with the virus or the bacterium present in the environment, the antibodies, produced following the vaccination, quickly recognize and destroy the micro-organism before it has the possibility of making us ill.
The vaccines that are inoculated with them contain pathogens that have been weakened so that the body can immunize against them without getting sick.
The vaccinations to which we are subjected increase the number of germs that our body can recognize.
The vaccinations have drastically reduced the cases of diseases caused by viruses, such as polio, chicken pox and measles, and other diseases such as influenza, hepatitis A, hepatitis B, and human papilloma virus.

What is an allergy?

Even allergies are immune reactions . Pollen, dust mites and sometimes the same food can cause allergies and are therefore called allergens . When the immune system fights substances that are not generally dangerous, an allergy occurs. Most allergies are caused by a group of immune system cells called mast cells.


The immune system at different stages of life: newborns

After birth, acquired (specific) immunity is not fully developed. However, newborns have some antibodies that have crossed the placenta during pregnancy. These antibodies protect infants from infections until their immune system is fully developed.

Newborns also receive antibodies through breast milk. ‘breastfeeding extends these benefits over time, contributing to the development of a  physiological intestinal flora , which is one of the first natural protection of the newborn.


A recent study shows that a sterile environment is even harmful to the baby, because it prevents the development of the immune system. ‘breastfeeding, on the contrary, stimulates and helps fight infections, asthma and allergies .
We have seen that babies who are breastfed have a different bacterial flora than artificially fed infants: this particular composition would seem to influence the development of the immune system, making the newborn even less subject to allergies caused by pets.   

In addition, exclusively breastfed babies have more bacteria than the bifidus family , which are important for digestion.


Weaning  can be a delicate moment for the baby. The introduction of new foods in fact changes its intestinal flora making it more vulnerable: at this stage some small digestive disorders could occur.
This is also the age when the child begins to touch everything and put everything in his mouth.  his contacts with the outside world are more numerous and discovers sociability and sharing,  including that of viruses! The immune system of children reaches full maturity at 4 years .

The immune system in the elderly

The immune system in the elderly

As we age, the immune system begins to lose strokes: this means that it becomes less effective in distinguishing the “self” from the “non self” , that is, it cannot distinguish foreign antigens. This lack of recognition can cause autoimmune diseases, very common in old age .

It also decreases the number of white blood cells that are responsible for responding to new antigens. Therefore, in elderly subjects, the organism is less able to recognize a new antigen and to defend itself from it.
The macrophages , which “eat” bacteria and other foreign cells, slowly destroying bacteria, cancer cells and other antigens. This slowdown could be the cause of the fact that tumors are more common in people of advanced age.


If the tolerance towards “self” fails, the cells of the immune system attack the cells of the body, exchanging them for enemy cells . This condition is called autoimmunity or autoimmune disease. It is still not known well why this happens but this leads to a condition in which one is particularly weak and exposed to meet autoimmune diseases.
A recent study would show that a high-fat, 

high-calorie diet can lead to the immune system . A risk whose effects continue even after having stopped consuming junk food.

There are many autoimmune diseases that can affect any part of the body. Among these are:
  • Systemic Lupus Erythematosus
  • rheumatoid arthritis
  • multiple sclerosis
  • Hashimoto’s Thyroiditis
  • Psoriasis.
The causes of this group of pathologies are not yet well known, but we think of a combination of genetic factors to which are added external precipitating factors such as stress, endocrine imbalances, infectious or viral agents that can induce chronic inflammatory states.
Autoimmune diseases are more common in women and for this reason we also think of estrogen involvement in contracting the disease.

How autoimmune diseases are treated

Autoimmune diseases are multifactorial so treatment and therapy must come from several fronts . Often the basis is genetic and to this we can add triggering factors such as drugs, infections (Staphylococcus, Candida, etc.) or hormonal imbalances.

Most patients with autoimmune diseases have Vitamin D deficiency , so it will be important to restore normal values ​​through appropriate supplementation (to be done under medical supervision).
Vitamin D can be accompanied by the use of edible oils such as currant oil, and some Omega-3s that can be very useful for controlling inflammation and systemic stress.
Therapies based on lactic ferments can help to have a healthier intestine by restoring the eubiosis, or the normal intestinal bacterial flora, while a glutamic supplement of about 5g a day can help restore the optimal permeability of the intestinal membrane.
In some cases autoimmune diseases induce structural damage to glands and / or organswhich are no longer able to perform their functions. In this case, conditions may arise in which the patient’s hormonal production is no longer sufficient and pharmacological treatment is required Example is Hashimoto’s Thyroiditis where levothyroxine sodium must necessarily be taken as an oral drug.


In order to prevent states such as those caused by intestinal dysbiosis, it would be good to have a healthy diet and lifestyle. In fact, not only an unbalanced diet, but also periods of high stress can be predisposing factors.
Prevention is based on lifestyle, but can also be done through diet; in detail the use of prebiotics and / or probiotics may be supportive.
The probiotics are live microorganisms (usually bacteria) that assumed in certain quantities confer benefits to health effects, the most famous belong to the genus Lactobacillus and Bifidobacterium, and can be easily taken in tablet form in order to restore a proper bacterial flora (yogurt and fermented foods it they are rich).
Instead, prebiotics are non-digestible ingredients (fibers) that provide health benefits by selectively stimulating the growth or activity of specific bacteria in the gastrointestinal tract. In addition to promoting the growth of “good” bacteria they have the ability to inhibit that of potentially harmful bacteria such as Clostridium or Escherichia Coli.
In short, a healthy life and a balanced diet make it possible not to undergo intestinal dysbiosis and at the same time are able to strengthen the immune system thanks to a healthier intestine.

When the immune system is weakened

When the immune system is weakened , or when it responds inadequately to the attack of viruses or bacteria, the consequence is the proliferation of continuous infections .

The most common symptoms when you have a weakened immune system are:
  • fatigue continues from when you wake up
  • faults and nausea caused by temperature changes
  • continuous colds and sore throats leading to flu
  • frequent reactions to pollen, dust or other external agents
  • wounds that do not heal, they become infected, become inflamed and hurt
To be sure that our immune system is weak, it is sufficient to do simple blood tests:
  • blood count , for white blood cell counts
  • lymphocyte count
  • lymphocytic typing , to assess whether there are deficits in a specific class of cells
  • ves , to check if there is an ongoing infection
  • immunoglobulin dosage to calculate the amount of individual immunoglobulin classes in the blood.

Why is the immune system weakened?

The immune system may be “unprepared”:
  • at the season changes
  • to the sudden passage from a warm to a cold environment (and vice versa)
  • in the long run, due to a lack of vitamins and minerals such as iron, magnesium, potassium and folic acid.
  • due to stress .
These situations can all weaken our immune system, making its protective action less effective  .

Diet to strengthen the immune system

healthy lifestyle and a balanced diet , rich in vitamins and minerals, can certainly help to have a strong and reactive immune system against external agents.

There are a number of foods that perform an immunomodulatory and anti-inflammatoryaction  , that is to say that can guarantee an adequate functioning of the body’s defense and protection systems. Let’s see what they are:
  • blue fish , then herring, mackerel, sardines, tuna and salmon. They are foods rich in arginine,  omega-3 fatty acids;
  • tenderloin, rib eye and baby walker but also octopus, milk and dairy products. These foods have in common the  zinc content , which is  essential for the proper functioning of the immune system;
  • grapes, pine nuts and cashews : all contain resveratrol,  a molecule of plant origin that boasts valuable anti-inflammatory, anti-tumor properties and protects the body from cardiovascular diseases;
  • kiwi, citrus fruits and green leafy vegetables:  they all contain high amounts of Vitamin C,  with known antiviral properties.

Supplements that improve immune defenses

When it is necessary to supplement the diet with the administration of nutrients useful to promote the immune system, two amino acids in particular are used:  glutamine and arginineArginine is found mainly in meat , while glutamine is found mainly in milk and cheese .

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