A Healthy Gut for Strong Immunity

For a strong immune system, you need a healthy gut

Our immune system is our first line of defence when exposed to a virus, particularly coronavirus. The intestinal flora supports the immune system and its adapted responses to infection. When a pathogen is detected, the immune system reacts against it, creating inflammation. This inflammation damages our tissues, and mild symptoms develop until recovery. If the immune system is impaired or overreactive, this inflammation gets out of hand, and severe symptoms appear. The interaction between gut and the immune system is essential in the body’s responses to infection.

What is the immune system?

The immune system’s primary role is to define what belongs to us and what does not belong to us. It is the central communication system of our body with the external environment. This system is very complex. It includes cells, molecules, antibodies, and physical barriers such as the skin and the intestinal mucosa barrier. All these elements work together to scan our environment, detect what is foreign to our body and eventually fight it.

When a pathogen enters our system, the immune system detects it, recognizes it, and starts a chain of reactions to fight it. These reactions release cytokines, molecules that act as messengers to the different cells, to coordinate the whole immune response. In the case of a viral infection, the appropriate answer of the immune system is to stop virus duplication, and the viral load decreases.

When our immune system is healthy and works well, these reactions create a natural and adapted inflammation and produce mild symptoms. When it is insufficient, the virus duplicates more and more in different cells, creating massive tissues damages. When our immune system is impaired or overreacting, the cytokines production and the inflammation gets out of hands, creating damage in the body, and severe symptoms can appear.

What is the intestinal mucosa?

The intestinal mucosa is a mucous membrane containing intestinal cells and molecules that hold these cells together. This mucous membrane acts as a selective barrier. On one hand, it prevents the entry into the body of pathogens and toxins present in the gut. On the other hand, it allows the absorption of nutrients and vitamins necessary for our health. When this mucous membrane is altered, undesirable molecules pass in our system, and nutrients are not well absorbed. The passage of toxic substances and pathogens into the general circulation is the starting point of many disorders, particularly infections.

Immune cells are also present in this mucous membrane. More than 70% of immune cells are found in the gut. Historically, food contained many pathogenic organisms, and the intestinal mucosa was an important centre for our protection against the environment. When intestinal immune cells spot a pathogen, they create inflammation on-site and send a signal to our whole immune system that there is an element to fight. Immune cells in the gut are often on the front line of our immune defence, explaining the importance of healthy intestinal mucosa for a strong immune system.

What is the intestinal flora?

The intestinal microbiota is more than 10,000 billion microorganisms (more than the number of cells in our entire body), primarily bacteria. Yeasts, viruses and parasites are also present at the digestive level but much less numerous than bacteria and do not seem to have the same positive interaction with our body.

There are 800 to 1000 different species of bacteria in our intestines. The way we are born influences the quality of our intestinal flora. In the womb, the baby is not in contact with bacteria. Its first contact is made at birth, either with the vaginal microbiota or the skin’s microbiota if the delivery is by caesarean section. From this first contact, the bacteria will colonize the gut. The microbiota fully develops during the first three years of life, influenced by diet, drug treatments and the environment. At three years old, our intestinal flora is fully defined. There is great diversity in the flora composition between individuals, and our intestinal flora is specific to each of us, like a fingerprint.

Food is digested in the stomach and the small intestine, where most nutrients are absorbed. But digestion does not stop there. Food migrates to the large intestine, where the intestinal flora digests it. Bacteria feed themselves mainly with insoluble fibers. While digesting these foods, bacteria also produce molecules that will act as messengers for our various organs. These molecules, called postbiotics, have been intensely studied in recent years. We are discovering more every day about new interactions between the gut and our different organs, showing the complexity and the essential role of the intestinal flora in our body.

Why does a strong immune system need a healthy gut?

The relationship between the immune system and intestinal flora is essential. The intestinal flora or microbiota are billions of healthy bacteria, which we need but do not belong to us. The immune system must find a way to differentiate these beneficial bacteria quickly from pathogens we are exposed to.

The development of the immune system occurs in the first years of life, at the same time as the intestinal microbiota. It seems that the two develop in symbiosis during early childhood. While the immune system accepts the gut colonization by healthy bacteria, the microbiota, in return, develops capacities to calibrate and support the immune system.

The intestinal flora bacteria colonize the intestinal mucosa surface. By taking the space on the membrane, they prevent other organisms from growing. But it is not the only way they are supporting the immune system. The microbiota secretes molecules and messengers to support and stimulate the immune system. In the early stage of an infection, the cooperation between the gut and immune system seems essential to create an appropriate response.

When the intestinal flora is unbalanced, what we call a dysbiosis, these messages get through badly, and the immune system’s response can then be affected and inadequate. In addition, when inflammation occurs in our digestive system due to excessive permeability of the wall or an imbalance of the intestinal flora, the immune system finds itself busy fighting against this inflammation and protects us less from infectious agents. People who have inflammation and dysbiosis are then more susceptible to infections.

How do you know your intestinal flora is out of balance?

The symptoms reflecting an imbalanced microbiota are varied. Symptoms such as bloating, digestive disorders, food intolerances, skin problems or even anxiety and mood disorders can be related to dysbiosis. Many factors influence gut health. An unbalanced diet, lack of exercise, the daily stress we can be exposed to, and hormonal changes can all be the starting point of dysbiosis.

Researchers have found more recently that some species are essential to the quality of the intestinal surface and therefore support the immune response. In the case of the coronavirus virus, several studies have shown a real correlation between the deficit of certain pillar species, like Bifidobacterium bifidum, Bifidobacterium longum, Faecaibacterium prausnitzii, the severity of symptoms and an increased rate of hospitalization among patients infected with the virus.

It is now possible to perform a qPCR test to analyze the intestinal flora and highlight an imbalance and a deficiency of these bacteria streams associated with lack of efficiency of our immune system response infection. A simple test like a qPCR microbiome core testing panel can show an eventual dysbiosis and deficit in these essential bacteria streams.

Restoring the intestinal flora is often a long process. It requires a good diet, an improvement in lifestyle and a combination of prebiotics and prebiotics. Practicing regular exercise, stress management, and anxiety management can improve the quality of the intestinal flora and directly boost our immune system. Restoring the intestinal flora often requires a holistic approach to things. Complementary medicine such as hypnosis, reiki, acupuncture, osteopathy, or even lymphatic drainage can all be a real help in restoring our microbiota and thus allowing us to strengthen our immune system.