Compound in apples fights deadly E. coli O157:H7

Kathleen Blanchard's picture
Compound in apples could lower the risk of E. coli infection

A compound found in apples has been shown by researchers to inhibit toxins and other genes in a strain of E coli infection that can be deadly. The compound, called phloretin, suppresses the effect of the bacterium Escherechia coli O157:H7 that comes from contaminated food.

Escherechia coli O157:H7 causes hemorrhage in the intestines. There is no treatment for the food-borne bacteria, which is resistant to antibiotic therapy.

Elderly people and infants are especially susceptible for becoming critically ill from E coli. The bacterium is virulent and can even lead to kidney failure.

In the study, published in the journal Infection and Immunology, researchers were able to show that the anti-oxidant compound from apples had anti-inflammatory properties and reduced biofilm formation on the surface of cells in the colon that make the virulent strain of E. coli 0157:H7 impervious to antibiotics.


At the same time phloretin did not harm beneficial E coli K-12 strains that reside in the intestine and can actually boost immunity.

In addition to its anti- E. coli O157:H7 biofilm activity, phloretin “accounts in part for the antioxidant capacity of apples and it also shows anti-inflammatory activity," says corresponding author Jintae Lee of Yeungnam University, Gyeongsan, Korea.

He also said the study results confirmed phloretin in apples has anti-inflammatory properties that the researchers found in lab and live colitis models. The effect of phloretin was stronger than the drug 5-aminosalicylic acid used to treat inflammatory bowel disease.

"This study suggests that phloretin in apples could reduce the risk of E. coli O157:H7 infection and intestinal inflammation”, said Lee.

J.-H. Lee, S.C. Regmi, J.-A. Kim, M.H. Cho, H. Yun, C.-S. Lee, and J. Lee, 2011.
"Apple flavonoid phloretin inhibits Escherichia coli O157:H7 biofilm formation and ameliorates colon inflammation in rats"
Infect. Immun. 79:4819-4827

Image credit: Morguefile