Does Olive Leaf Extract Kill Good Bacteria in the Intestine?

Olive leaf extract is a type of herb that may provide some health benefits, although more research is necessary to determine this. There is some indication that olive leaf extract provides some antimicrobial activity, which may give it the ability to destroy certain types of bacteria, including the good bacteria that reside in your intestines. Talk to your doctor before taking olive leaf extract to treat a medical condition, especially if you are pregnant or nursing.

Intestinal Bacteria

Your intestines contain hundreds of different types of bacteria that help to make up the intestinal flora in your digestive tract. While some bacteria can be potentially dangerous, most intestinal bacteria are beneficial organisms that perform essential functions. In healthy digestive tracts, the beneficial bacteria keep the harmful ones in check. Antibiotics can upset this delicate balance, killing both the good and bad bacteria within your body, including those inside your intestines. By destroying the beneficial bacteria, medications with antibiotic properties can increase your risk of colitis and antibiotic-associated diarrhea.

Olive Leaf Extract

Oleuropein is the active ingredient in olive leaf extract. Your body breaks down oleuropein into enolinate. Proponents of olive leaf extract remedies claim this substance acts as an antibiotic on bad bacteria, while supporting the activities of beneficial bacteria. There is no evidence or scientific justification to support these claims.

Bacteriacidal Properties

Olive leaf extract is not a standard medicine or remedy for treating bacterial infections. Although this substance has a long history of use as a treatment for cleaning wounds, there is no scientific evidence that confirms the antibiotic properties of oleuropein or enolinate.


Prescription antibiotics tend to kill both good and bad bacteria, often leading to digestive problems that occur after the loss of beneficial bacteria in the intestinal tract. There is insufficient research regarding the benefits and side effects of taking olive leaf extract, although it appears to be fairly safe for most adults. Consuming probiotics may help balance the intestinal bacteria and restore beneficial bacteria killed from taking antibiotics. Preliminary research shows that probiotics, especially S. boulardi and Lactobacillus GG, may help reduce the risk of diarrhea that occurs with antibiotic treatment, according to the University of Maryland Medical Center 23.