ose Clifford is eating lots of yogurt for her gastrointestinal health. Doctors diagnosed her as having helicobacter pylori bacteria, which is implicated as one of the major causes of gastric ulcers.
Along with prescription medication, she is trying to crowd out the bad bacteria with live and active cultures, or probiotics, which are found in yogurt, she says.
"Antibiotics kill good and bad bacteria," says Ms. Clifford, who is a research nutritionist at MedStar Research Institute in Southeast. She is a registered and licensed dietitian. "Probiotics help restore the normal balance to the gastrointestinal tract."
Many doctors say probiotics, or beneficial bacteria, can be used to improve digestion and overall health. The World Health Organization defines probiotics as "live microorganisms, which, when administered in adequate amounts, confer a health benefit on the host." People can consume probiotics through dietary supplements, or foods, such as yogurt.
"There is a lot of bacteria on your skin, mouth and GI tract," Ms. Clifford says. "It all plays a role in people's health. It helps to keep the intestinal tract healthy. It acts like a barrier, to keep good things in and bad things out. It absorbs nutrients."
Probiotics have been known to have anti-diarrheal effects, she says. Also, some women might take probiotics to help prevent and treat vaginal yeast infections.
Because probiotic strands are unstable, they are only present in a few foods, such as yogurt and kefir, a fermented milk drink. When the food products and dietary supplements are refrigerated, it helps to extend their shelf life, she says.
While probiotics are sold as dietary supplements, yogurt not only has probiotics, but also nutritional benefits, says Robert Garfield, senior vice president of the National Yogurt Association in McLean.
The yogurt with the biggest health benefits has a seal on the package stating: "live and active cultures," he says.
"That means it has 100 million live and active cultures per gram at the time of production," Mr. Garfield says.
Although all yogurts are made with standardized cultures, such as lactobacillus bulgaricus and streptococcus thermophilus, the yogurt with the most live and active cultures after production is marked with the organization's seal, he says.
Additional cultures also can be added to the yogurt during production, he says. Many yogurts have strands of acidophilus, bifidus and casei.
When the seal is present, it also means that 38 days after production, another test takes place to measure the cultures in the product and see if they will grow, he says.
"At the end of shelf life, there can be no guarantee that there will be 100 million cultures in there," Mr. Garfield says. "We recommend 10 million. Most testing shows there are at least 10 million at the end of shelf life."
Although yogurt has nutritional benefits, sometimes specialized dietary supplements are a helpful route, says Jordan Rubin, founder and chief executive officer of Garden of Life, based in West Palm Beach, Fla. He is the author of "The Maker's Diet" and a naturopathic practitioner.
However, not all dietary supplements are created equal, he says. In 1996, when trying to recover from Crohn's disease, he says he took bottles of probiotics and didn't get any better. Taking homeostatic soil organisms, which are beneficial bacteria found in dirt, finally worked the best for him. This included microorganisms from the bacilli family and saccharomyces, a friendly yeast.
"I started to see a change pretty quickly," Mr. Rubin says. "Around day 30, I started to feel better. In 12 weeks, I went from death to life, more or less."
At the time, he was taking the equivalent of 12 capsules a day of Primal Defense, a probiotic formula he developed and sells through his company, Garden of Life. It has powdered vegetable extracts and organic plant-based minerals, along with homeostatic soil organisms.
After starting the regimen, he says he actually started feeling much worse before he started to feel better as his body went through an initial detox period.
"I always said, 'Whatever helps me, I'm going to help the world with it,' " Mr. Rubin says. "It started with me stocking shelves at a health food store."
Probiotics can help treat a myriad of conditions, such as irritable bowel syndrome and constipation, Mr. Rubin says. He estimates that 70 percent of the immune system is in the gut-associated lymphatic tissue. Therefore, strengthening the gut helps to strengthen the overall immune system, Mr. Rubin says.
Despite what supporters say, unless someone has taken a long regimen of antibiotics, it isn't usually necessary to recommend probiotics, says Ryan Andrews, dietitian and exercise physiologist at Johns Hopkins Weight Management Center in Baltimore.
"We have some people who swear by them," Mr. Andrews says. "They say, 'When I don't take the Activia drink, I don't feel right.' "
However, Mr. Andrews acknowledges that there are a lot of potential benefits from probiotics, but enough testing hasn't been completed to know the full effects, he says. Activia is a yogurt drink manufactured by Dannon.
"I read that they are testing out probiotics in infants, looking at the feeding tolerance," Mr. Andrews says. "I've read a couple studies that show that feeding tolerance is improved when they take a round of probiotics, using a liquid form of probiotic."
After patients have taken a round of antibiotics for urinary tract infections or sinus infections, it should be followed by a round of probiotics, says Dr. Ken Mirkin, chief of gastroenterology at Inova Fairfax in Falls Church.
"It's not a medication," Dr. Mirkin says. "It's treated as a food supplement. There isn't any FDA control. People have to read labels to see what they're getting. There are many different probiotics. Know what you are taking and why you are taking it."
Most patients need to take probiotics for three to four weeks in order for them to be effective, Dr. Mirkin says.
"If you increase the population of certain kinds of bacteria, it inhibits the growth of bad bacteria," Dr. Mirkin says. "They compete for the substrates and the food. It's survival of the fittest. If you pour in millions of colonies of good bacteria, the bad guys will not survive, just by sheer numbers."