What Even Is A "Natural Antibiotic"?

"Natural antibiotics" sounds like something you would frantically google when you're getting a cold and want to cook up a home remedy. Even though you know you should probably see a doctor, you might cautiously experiment with some holistic "cures." It's smart to be somewhat skeptical of anything that claims to be "natural" and "cure" an infection, but interestingly there is such a thing as a natural antibiotic.

Antibiotics, by definition, are anything that kills bacteria, a virus, or a fungus, says Zhaoping Li, MD, PhD, professor of medicine and chief of the division of clinical nutrition at the University of California, Los Angeles. The first antibiotic that humans discovered, penicillin, was made from bacteria from plants, but it's now predominantly made from synthetic materials, she says. "In a sense, [penicillin is] kind of natural, and that's how everything started," she says. Lots of plants make their own bacteria-fighting compounds to survive, and human beings can take advantage of this by eating them, she says.

So, what are these so-called natural antibiotics hiding in your pantry? The most famous one is cranberry, Dr. Li says. You've probably heard that cranberry juice will "cure a urinary tract infection," but that's not exactly how it works, she says. What cranberry can do is make the bacteria "less likely or less capable to attach itself to our urethra, therefore they can't cause trouble," she says.

A couple other foods provide a similar bacteria-balancing benefit. For example, dried pomegranate peel is believed to support good bacteria and inhibit bad bacteria, which may help treat diarrhea and certain gut infections, like C.diff, Dr. Li says. Pomegranate is often used in Traditional Chinese Medicine, but has recently been studied and confirmed by Western doctors. Green tea, which is used in lots of acne products, is also known to fight bacteria, and garlic is fine for supporting good bacteria, she says.

Before you stock up on cranberries and garlic, keep in mind that these foods aren't meant to replace antibiotic drugs, but rather they're foods that contain important compounds that can restore the good and bad bacteria in your body, Dr. Li says. "In the last 10 years in the medical field, we're still changing from the concept of, All bacterias are bad and we've got to kill them all, to, Actually, we really need to restore the balance of bacteria," she says. If you have a mild illness, like if you think you're getting a cold, then eating some of these will help "bring the garden back to beautiful bloom and harmony," she says. But for more serious infections, you've got to go see a doctor, so they can figure out the exact thing causing it and treat it with a targeted medication.

Also worth noting: These are just some of the foods that doctors have begun researching, so there are likely more "natural antibiotics" out there. Eating all different kinds of vegetables and fibrous foods is another way to feed your good bacteria and suppress the bad ones, Dr. Li says. You should keep your body's bacteria in mind all the time, not just when you think you're getting sick, because they are essential. "We're living in essentially an ocean of microbes, and it's important we get surrounded by the right guys," she says. If you're able to take care of your own "microbe society," then it'll prevent infections, and keep you healthy.