It is well-known that if you completely paralyze a person’s immune system — or even impair critical parts of it — all the antibiotics in the world can’t cure even a simple infection.

This fact has been proven not just in laboratory animals, but also in clinical cases involving people.

What many people, even some doctors, do not know is that the function of antibiotics is simply to make it easier for the body’s immune system to eliminate an invading organism.

Take, for instance, the case of a person who has poorly controlled diabetes, which is a condition known to suppress cell-mediated immunity — the type of immunity that is most critical to fighting infections.

Let’s say this person develops a serious Staph infection of the big toe. In many cases involving diabetics, an infection cannot be controlled even if they are taking a number of powerful antibiotics.

This is because the person’s natural immunity is so badly impaired. Eventually amputation becomes necessary.

Other immune-suppressing diseases can lead to uncontrollable, even fatal infections that would be a minor problem for a person with a normal immune system.

Such conditions include kidney disease, malignant tumors, autoimmune diseases, and HIV.

We also know that cell-mediated immunity is impaired in many older individuals. For them, even minor infections can be life-threatening.

This is why we hear vaccine manufacturers constantly advertising their vaccines as a way to prevent pneumonia in older people.

In a typical case of infection, the person would be hospitalized and started on antibiotics — usually several. In most cases, these antibiotics will be powerful, broad-spectrum ones that kill a lot of different types of bacteria. Those antibiotics may be administered for weeks or even months.

Rarely is the health of the patient’s immune system considered. Little effort is made to improve his or her immune function during treatment.

A hundred years ago, we might have accepted that there was little doctors could do to improve immune function.

But in today’s world, we have a much greater understanding of the immune system — how it works and how to improve its function.