The latest issue of the Mayo Clinic Health Letter has drawn attention to the digestive health benefits of probiotics.

According to the newsletter, probiotics appear to change how the immune system reacts to invading microorganisms by enhancing the system and also calming it when it overreacts, although the exact mechanisms are not fully understood.

They also help restore or maintain proper bacteria balance in the intestines. That balance can be upset by antibiotics, antigens causing infections, stress or even travel. In particular, strains of lactobacillus and Saccharomyces boulardii seem to be the most effective in treating diarrhea, it says.

The newsletter also comes shortly after the publication of a Finnish study which found that probiotics may prevent pregnancy-related fat.

Specifically, the scientists found that women who start taking probiotics in the first trimester of pregnancy are less likely to develop obesity within the first year of giving birth.

Those who would like to control their weight or improve their digestive health may consider nutritional supplements containing probiotics. They are also available in select dairy products.