JERUSALEM, Nov. 8 (Xinhua) -- A new Israeli-U.S. study found that probiotic bacteria, considered "friendly" to the human body, can cause life-threatening sepsis in children hospitalized at intensive care, Hebrew language newspaper Haaretz reported Friday.
Probiotics are foods or supplements that contain friendly bacteria and aim to balance the harmful bacteria in the gut and mouth.
Probiotics are attributed to the ability to prevent diseases, improve digestive function and strengthen the immune system.
Consumers worldwide spend billions of dollars each year on probiotic-enriched foods, as well as over-the-counter supplements in pill and powder form.
The use of these bacteria is also steadily expanding and is often given in hospitals.
However, some doctors and scientists argue that probiotics are of no use and that their contribution has never been scientifically proven.
The new study, conducted by researchers from the Israel Institute of Technology (Technion) and Boston Children's Hospital, and published in the journal Nature Medicine, examined 22,174 ICU (intensive care unit) patients, of whom 552 were treated with probiotics.
It turned out that 6 of the 552 children had been diagnosed with infection, while all the other patients were not diagnosed with a similar infection.
Although only 1.1 percent of the probiotic-treated children suffered infection, a thorough genetic examination found that the infections were caused by the probiotics.
In one case, the probiotic treatment even created a mutation of antibiotic-resistant bacteria.
Such severe infections may lead to sepsis, a life-threatening medical condition caused by the body's immune response to the infections.