Is it true that substances are carried from the blood in capillaries to tissues in a liquid called tissue fluid? What is the extracellular fluid in most tissues is called? What is a tissue fluid?   Tissue fluid is the the fluid that surrounds the bodies cells, or technically it bathes the cells in the body or cleans them.
The most important function of immune system is to defend the body from different disease causing pathogens. Whenever there is pathology in human body, immune system is activated to protect the vital tissues from harm.
As stated above, your gut flora are key players in your health. Two of the most important roles have to do with immune system protection and metabolism. For these important functions, there needs to be an optimal preponderance of friendly bacteria. Let's take a look at each of these functions in turn: