Gut Health

Immune System 101: From T-Cells to Herd Immunity to the Gut-Immune Connection

You come in contact with more than 60,000 germs every day.

They linger on every surface you – and everyone else – touch, from doorknobs to elevator buttons to shopping carts to restaurant menus. 

Some microbes spread through the air, like after someone sneezes, coughs, or shouts. Others sneak by in food and water.

All of these germs make you vulnerable to infection. 

But, with an optimized immune system, most of them won’t make you sick.

To keep your immune system in the fighting form, it helps to understand how it works and how you can support healthy immune function.

Two Types of Immunity

The whole of your immune system can be divided into two main categories: innate immunity and adaptive immunity. These two crucial groupings work together to keep you healthy from the day you’re born.

Innate immunity is your natural immunity, the immune system you’re born with – kind of like a built-in default system. It offers general protection against infectious microbes like bacteria and viruses. This section of your immune system can identify invaders as “foreign” (not self) and figure out whether they’re dangerous.

Adaptive immunity is the process through which your immune system learns based on the germs you encounter, either through infections or vaccinations. Your adaptive immune system collects information about those microbes and how it was able to defeat them. It builds a sort of catalog that it can refer back to when a germ shows up. Then it uses targeted defense strategies that have worked in the past to take those microbes down.

Your Immune System Has Many Soldiers

To keep you safe against the thousands of threats you face very day, your immune system has an enormous team in place to protect you

Example: Your spleen, bone marrow, and thymus work to create the cells your immune system needs to fight germs.

There are several different types of immune cells, and they all bring unique germ-fighting skills to the bodily battle for your health:

>> Phagocytes are white blood cells that chew up infectious microbes

>> Lymphocytes help your immune system remember invaders it’s faced and how it destroyed them

>> B-cells (B lymphocytes) patrol for germs, identify them, and tag them with antibodies

>> Antibodies, also called immunoglobulins, lock on to and tag specific bacteria and viruses 

>> T-cells (T lymphocytes) lock on to and destroy the germs tagged by the antibodies

>> NK-cells, or natural killer cells, offer first line defense and general protection (as part of innate immunity) against viruses and cancer cells 

Sometimes, though, our immune systems face a new infectious microbe, one that our body hasn’t had a chance to develop defenses against. In times like these, we can gain some protection from herd immunity.

herd immunity

How Herd Immunity Works 

When a big enough percentage of the population becomes immune to an infection, it reduces the risk of person-to-person sp