Reported in the February 2004 issue of the journal Gastroenterology by researchers at the University of California, San Diego (UCSD) School of Medicine and the Shaare Zedek Medical Center in Jerusalem, Israel, the findings offer the potential to use inactivated probiotics in food products. In addition, the study provides a mechanism to determine and to select which probiotic bacteria are best for patients with IBD.
A probiotic is a bacterial organism that contributes to the health and balance of the intestinal tract. Although recent medical studies have proven the therapeutic benefit of these good bacteria, their use dates back thousands of years. People in ancient Babylon, for example, used sour milk to alleviate gastrointestinal problems.
Although the effectiveness of these bacteria has been attributed to their live, metabolic activity, viable probiotics can't be added to food because they induce fermentation, changing the taste, texture and freshness on an hourly basis. For that reason, the bacteria have only been used in a very narrow range of products such as yogurt.
"Our goal was to address whether the metabolic activity of probiotics was mandatory for their protective effect," said the study's senior author, Eyal Raz, M.D., professor of medicine at UCSD. Raz noted that previous studies had tried heat killing of probiotics to inactivate them, but this process destroyed the cellular structure and beneficial aspects. In the new experiments, the team used gamma radiation on the bacteria, reducing metabolic activity to a minimum.