Immunity, as a subject, certainly raises a web of interrelated questions. Why do some people have a weak immune system? What is the role of gut health in immunity?

Moving forward in our line of enquiry, we delve into the concept of inflammation, how and why it occurs and what it has to do with the immune system. 

What happens when a pathogen enters our body?

We’ve explored this in detail here, including how the innate immune cells kill the pathogens by way of phagocytosis, which means they devour the foreign substance that is a threat and destroy it.

While this process of phagocytosis is being carried out, the confrontation between the immune cells and the pathogen often sets off the inflammatory response.  

What is inflammation?

Our immune system’s response to an intrusion by an irritant – which could be a pathogen, or even just a thorn – is inflammation. The inflammation starts from the time the pathogen or foreign body enters the body. 

What are the signs of inflammation?

When the wound becomes red, and is swollen and painful, you know that inflammation has set in. The site of inflammation may also feel hot, and if the inflammation has occurred at a joint, it may be difficult to use it. 

In case of severe inflammation, the person may also suffer from fever and exhaustion; this is a sign that the immune system is working hard. There may be more antibodies and immune cells fighting the infections and more immune cells can be seen in the blood(2).

What actually happens at the site of inflammation?

When there is inflammation, a complex process occurs which involves many cells of the immune system – the immune cells secrete various substances which are called inflammatory mediators. These cause:

  1. Dilation of blood vessels: These include hormones such as bradykinin and histamine, which make the blood vessels around the wound dilate. This widening of the small blood vessels makes the wound appear red, but it also helps in more immune cells getting to the wound spot to fight the infection and heal it.
  2. Pain: The hormones also irritate the nerve endings at the wound, which is why one will register pain from the inflammation site. There is a positive side to this pain too; because of it, we take precautions to protect this area from further damage.
  3. Swelling: The inflammation mediators also see to it that more immune cells pass out of the blood vessels into the affected area to speed up the process of repair. Because of the fluid accumulation in the affected tissue swelling might be observed, which eventually subsides when the fluid passes on into other tissues.

Here are other ways that doctors diagnose inflammation or chronic inflammation.

Is inflammation helpful to our body?

We can say that inflammation is generally helpful to our body. But in some cases, such as rheumatoid arthritis and psoriasis inflammation, it is chronic and the reaction is against the body’s own cells; this can lead to serious health issues which are called autoimmune disorders.

Inflammation is a process that is crucial for healing. That said, if the inflammation is not regulated, it can become a case of chronic inflammation, which leads to severe health disorders such as rheumatoid arthritis.

Remember Dr. Jekyll and Mr. Hyde? Xu and Larbi (2017) interestingly likens “Dr Jekyll’ to the expected inflammation and immune response in general and the “Mr. Hyde” effect to dysregulated inflammation(3).

What does inflammation have to do with gut health?

Inflammation can be a symptom of a lack of diversity and resilience in gut microbes or, in other words, an imbalanced immune response.

As we have discussed here, an alliance between the immune system and gut microbiota is necessary to protect against pathogens. However, in some high-income countries, the overuse of antibiotics and changes in diet have caused a microbiota that are not capable of establishing balanced immune responses. This may account for the dramatic rise in autoimmune and inflammatory disorders to an extent. 

Simply put-

Uncontrolled immune response against the self, microbiota or environmental antigens can cause health issues such as allergies, autoimmune and inflammatory disorders.(6)

Why has inflammation been receiving so much interest recently?

Inflammation in the case of infectious diseases is already a well-known phenomenon. What’s new is that researchers think inflammation may play an important role in non-infectious chronic diseases such as cancer and autoimmune disorders(4). Why do some people have a weak immune system?

This opens up a whole avenue of research where treatment for inflammation, specifically, in these disorders can be worked out, which means these disorders can be stopped in their tracks in the initial stages itself. 

If new research in the field of controlling and treating inflammation is successful and the results help in making sure inflammation does not become dysregulated, it would be a breakthrough that may help in treating many chronic diseases such as rheumatoid arthritis, asthma, sinusitis etc.Anti-inflammatory drugs and anti-inflammatory foods – such as Astragalus, Panax ginseng, Angelica sinensis – which are also termed as adaptogens, may play a vital role in the treatment and prevention of infectious and non-infectious diseases(5). Here’s more on how adaptogens can affect immunity, and here are other measures to boost immune system.