To learn more about how probiotics can help people live a healthy lifestyle, we talked to registered dietician Leslie Bonci, the director of sports medicine nutrition for the Department of Orthopedic Surgery and the Center for Sports Medicine at the University of Pittsburgh Medical Center. Ms. Bonci is a professor and a nutrition consultant for the school's department of athletics and for professional athletic teams, including the Pittsburgh Steelers, Cincinnati Reds and Toronto Blue Jays. In addition, she is the company nutritionist for the Pittsburgh Ballet Theatre and the consulting nutritionist for the U.S.Olympic Canoe and Kayak Team. To maintain a healthy lifestyle, Ms. Bonci recommends that her clients include probiotics into their daily diets. But non-athletes can benefit greatly from probiotics, too, she says.

As a nutrition consultant, why do you recommend probiotics?

What we put in our bodies is one of the few things in our lives over which we have control. So making wise food choices that help our bodies' natural defense just make sense. Consuming certain strains of probiotics can help strengthen the body's defense system by providing a regular source of "friendly" bacteria to the intestinal tract. This has a direct effect on staying healthy because approximately 70 percent of our bodies' immune system is located in the digestive tract.

Are probiotics particularly beneficial for everyone of all ages?

Probiotics are beneficial for people of all activity levels and ages. There's research to suggest that probiotics may be particularly helpful for children whose developing immune systems are faced with new germs and allergens every day. But at any age, the occasional stresses of daily living-such as working long hours or getting insufficient sleep - can contribute to a decrease in the amount of good bacteria in your intestinal tract, which in turn, can weaken the body's natural defenses. In my line of work, I recommend that people who exercise include specific protiotics in their diets because they have rigorous schedules and don't always eat or sleep properly. Consuming probiotics in a yogurt or dairy drink is something simple and cost-effective that they can do to help keep their bodies' defenses strong and help restore the proper amount of "friendly" bacteria with minimal effort.

How can probiotics help you stay healthy?

Research is continuing to uncover myriad potential benefits of probiotics. For example, results of studies with both animals and humans suggest that regular consumption of certain probiotics dairy products may have an impact on cholesterol.¹ However, more research needs to be done in this area. Other research suggests that specific probiotics may play a role in helping to lower blood pressure and decrease symptoms of lactose intolerance. While more research is needed to understand all the benefits probiotics may offer, we do know that maintaining a balance of bacteria within the digestive tract can offer important benefits, such as helping to strengthen the body's defenses.

You've talked about probiotics' role in helping people stay healthy. Can they help you when you're sick?

Certain strains of probiotics can help with intestinal problems such as antibiotic associated (AAD) diarrhea. Research has shown that specific strains of probiotics helped reduce the duration of AAD both in children and in adults.² The most important thing to note is that probiotics have been helping people stay healthy for years.

Does it matter whether you consume probiotics in food or in supplements?

I'm a strong believer that people should get probiotics through food sources because they will get other nutritional benefits as well. For example, if you have a probiotic yogurt daily you're not only getting probiotics but also protein and important minerals including calcium to help build strong bones. People eat every day, but they take supplements irregularly. As probiotics need to be consumed regularly, people are more likely to make them a habit if they are part of good-tasting food like yogurt or cultured daily drinks

Are there right and wrong ways to consume probiotics?

The one thing you shouldn't do is heat yogurt with probiotics because that will kill off the good bacteria. People who have a dairy allergy might want to avoid yogurt products; however, research suggests that people who are lactose intolerant may be able to more easily tolerate dairy products that include probiotics.³ Most importantly, you need to read packaging carefully to be sure that probiotics are in the foods you're eating contain viable probiotics cultures and that the benefits are clinically proven - yogurt covered raisins won't count!

¹ Pereira DI, Gibson GR Effects of consumption of probiotics and prebiotics on serum lipid levels in humans. Rev Biochem Mol Biol 2002;37(4):259-281

² Hickson M, D'Souza AL, Muthu N, et al (2007). "Use of probiotic Lactobacillus preparation to prevent diarrhea associated with antibiotics: randomized double blind placebo controlled trial". BMJ 335(7610): 80.

³ C.M.Kotz et. al. (J. Dairy Sci. 1993 Dec:77[12]; 3538-44)