Seeking Ferment

Chicory, blue cheese and yogurt may not be on your daily menu, but these foods are emerging as possible new ways to prevent -- and perhaps treat -- a host of common ailments, from itchy eczema to traveler's diarrhea.

It all comes down to healthy bacteria.

Trillions of these microscopic organisms -- more than the number of cells elsewhere in the body as a whole -- populate the gastrointestinal tract, especially the colon. There they serve as a key line of defense against harmful bacteria, viruses and toxins that attempt to invade the body through the intestines.

"It is becoming more and more apparent that an appropriate microbial balance in the intestine is crucial for human health," note the University of Munich's Ilse J. Broekaert and Harvard University's W. Allan Walker in a review article published recently in Nutrition Today.

As the team reports, changes in diet -- for example, decreased consumption of fermented foods such as blue cheese and buttermilk -- have altered the natural balance in the intestines for many people. Increased use of antibiotics has also taken a toll on healthy bacteria.

That shift comes just as scientists better understand the value of these beneficial organisms, which have tongue-twisting names but are known collectively as probiotics. Among the leading strains are bifidobacteria and lactobacillus.

Studies show that when probiotics are given to children with diarrhea, they can shorten the illness' duration by a day. They also boost immune response to polio and rotavirus vaccinations and cut by up to 40 percent the diarrhea linked with antibiotic use.

There's also evidence that they can help reduce the bloating and flatulence of irritable bowel syndrome, inhibit growth of the bacteria responsible for stomach ulcers and boost effectiveness of drug treatment for this common disorder. "Yogurts containing live probiotics could become inexpensive tools for the treatment" of ulcers, suggests Broekaert and Walker in Nutrition Today.

There seem to be significant benefits outside the gastrointestinal tract, too, including improved overall immunity, possible prevention of some types of cancer and even better skin. One study has found that probiotics significantly reduced eczema symptoms in children. Another has found that infants born to women with a family history of eczema were 50 percent less likely to develop the disorder in the first four years of life when their mothers took probiotics during the last month of pregnancy and the first few months of breast-feeding.

Despite their promise, however, probiotics may not be for everyone. People whose immune systems are compromised by cancer chemotherapy, HIV or medication to prevent organ transplant rejection could be at risk for rampant infections from probiotics. But in healthy people, "the use of probiotics is unlikely to cause bacterial infections," Broekaert and Walker conclude.

Here are some foods and tips to help boost your healthy bacteria: