Your body contains upwards of 90 Trillion (with a ‘T’) bacterial cells, each one of which is its own entity, with its own DNA and purpose for living. New bacteria climb aboard every single day, and some of those freeloaders can cause you serious harm.
However, the majority of gut bacteria are essential for digestion; without these helpful stowaways, your body would be unable to process food into energy.
How does your body know which bacterial cells need to be removed?
Enter the T cell, specialized immune responders that your body creates to kill unwanted visitors by enveloping and destroying them. However, when you consider that the bacterial diversity of your body is far greater than that of mammals on Earth, it becomes evident that locating the evildoers in a sea of friendly cells is no easy task.
So how does the T cell know how to determine friend from foe?
Something called a regulatory T cell, or TReg.
Regulatory T cells help promote tolerance in the body by suppressing the response of other cells. When they work their magic all is fine, but when the regulatory T cell population is weak or malfunctioning, autoimmune disorders such as ulcerative colitis and Crohn’s Disease are the result. In cases like this your body over-reacts, killing the good bacteria along with the bad.
This essential gut-bacteria is one group that you don’t want to mount an immune response against. In fact, you need the Tregs’ help in inducing tolerance to these bacteria if you want to treat Crohn’s and other inflammatory bowel disease. —Dr. Leszek Ignatowicz
But where do Regulatory T cells get their know-how?
Now we know. It’s the Thymus.
It was thought that T cells learned to accept our more useful digestive bacteria once they arrived in the gut. However, a new study published this month in Nature has shown that the vast majority of these helpful servants come from a small organ near the heart called the Thymus.
And you probably didn’t even know you had one.
This discovery will help researchers battling immune-response diseases such as Crohn’s by providing a strategic path toward increasing the body’s regulatory T cell population. By increasing the output of the Thymus in this regard, autoimmune disorders may be cured or prevented. This has already been shown in mice that were bred with an ulcerative colitis-like disease.
The next step could be displaying this effect in human beings.