Antibiotics are medicinal products that have an anti-bacterial effect - they either kill bacteria in the system or keep them from reproducing, allowing the infected body to heal by producing its own defenses and overcome the infection. When antibiotics were isolated in the mid-twentieth century, they were widely hailed as 'wonder drugs' and indeed, formerly life-threatening infections could now be easily cured within a few days.

The most widely known antibiotic is perhaps penicillin, famously made from mold. When it was introduced, many of the sexually transmitted diseases such as gonorrhea went from being a shameful and life changing event to an embarrassing trip to the doctors.

One of the most prevalent and unstoppable myths about antibiotics is that they can cure a cold. Antibiotics work against bacterial infections, and colds are caused by viruses - therefore, a course of antibiotics will do nothing but perhaps kill off the body's own population of beneficial bacteria, leaving the cold to run its natural course. Nevertheless, patients often pressure their doctors into prescribing antibiotics when they come down with a cold or the flu.

One side effect of taking antibiotics for an infection is that it can leave the body defenseless against other non-bacterial types of infections, and for many women, this means a yeast infection, which is fungal. The fungus responsible for yeast infections is always present, and is kept from spreading by helpful bacteria in the digestive tract, which the antibiotics kill, or at least curtail, leaving the fungus to spread. Over-the-counter yeast infection products will usually work to alleviate a yeast infection.

Widespread use of antibiotics for non-medicinal purposes, such as in cattle feed and in antibacterial hand soaps, is causing concern in the medical and pharmaceutical industries, since it is responsible for the evolution of antibiotic resistant bacteria. Washing your hands with an antibacterial soap may make you feel cleaner, but any bacteria that survives the scrub is part of the bacterial population that is immune to that particular antibiotic, and thus all its descendants will be too. This has led to an "arms race" between bacteria and the drug manufacturers, with some antibiotics being held back or only minimally prescribed to prevent bacteria in the "wild" from adapting to them.

Antibiotics may seem like a recent innovation of the past hundred years, but indeed, many ancient civilizations had some understanding of the principle of antibiotics, and many herbs have anti-bacterial effects. One of the most widely known is common garlic. It is so effective at countering bacteria that over-consumption of garlic can have the same effect as antibiotics at leaving the body prey to non-bacterial infections by reducing the body's "good bacteria" population.