Good bacteria?

Dannon Yogurt used to run ads with a grainy black and white photograph showing a group of stern looking Russian women. The claim was that the women were all over 100 and the made it that far because of eating yogurt. While the folks at Dannon wanted us to believe that eating yogurt equals living longer, there’s actually a great deal of research going on to support yogurt’s beneficial properties.

It is the bacteria used in culturing the yogurt that is felt to be good for you. There are dozens of different ones used in making yogurt. Many are now being studied in placebo controlled trials, usually by giving study participants different bacteria (known as probiotics) in pill form.

In a study of 90 healthy Chinese men Hani El-Nezami and his colleagues (AJCN 2006;83:1199-1203) looked at the effect of probiotics on toxins produced by common fungi found in food. Known as aflatoxins these are considered potent cancer-causing chemicals and are associated with an increased risk of liver cancer in people who have been exposed to the Heptitis B Virus (HBV).

After 5 weeks of consuming the pills the two groups were studied. The group taking the probiotic preparation had a significant decrease in markers for aflatoxins. The marker, a breakdown product of the aflatoxin measured in the urine, decreased by 36% at the third week and 55% at the end of the study. The researchers consider that using probiotics may help prevent liver cancer in high risk groups. Clearly, larger studies are needed.

What this means for you

This is another of many studies on probiotics that are encouraging. Nothing is definitive and one can’t really make the leap of faith that pills and yogurt will have the same effect. Likewise, it can’t be recommended yet to take probiotics in pill form, but eating yogurt tastes good, is a good source of calcium and protein, and you may live to have your picture taken for a Dannon ad someday.

First posted: May 19, 2006