What do you think of when you hear the word “bacteria?” Do you think of microscopic bugs crawling around just waiting for the chance to make you sick? Do you quickly reach for the antibacterial soap in the hopes of washing them away? Or, perhaps, if you are sick, you rush to the doctor for an antibiotic — “biotic” meaning bacteria — hoping to “anti” away the bugs. But did you know that some of these bugs are actually quite good for you?
If you watch television or flip through magazines, chances are you do know about good bugs, or probiotics, thanks to actress Jamie Lee Curtis and her plugs for the yogurt Activia.
Ms. Curtis has certainly done an effective job of informing us about all the great things these naturally occurring bacteria can do for your digestive system. Probiotics, particularly Lactobacillus and Bifidobacterium, have been found to be helpful in easing digestive upset, keeping you regular, and protecting your overall GI (gastrointestinal) health.
But did you know that the benefits of probiotics reach far beyond the digestive system? According to two new studies, these microscopic powerhouses protect against oxidative stress and even help reduce upper respiratory infections.
Probiotics Protect Athletes Against Free Radical Damage
When you exercise, you naturally create energy. But just as a car using gasoline to produce energy releases harmful by-products of this process as exhaust, so, too, does your own body’s energy-producing efforts produce a dangerous by-product: free radicals.
Free radicals are highly reactive forms of oxygen that are missing an electron. When they come into contact with normal molecules, they try to steal an electron, damaging the healthy cell and its DNA. In fact, some estimates show that every cell in your body takes 10,000 oxidative hits to its DNA daily!
This is known as “oxidative stress,” and it has been linked to a wide range of health conditions, including heart disease, high blood pressure, high cholesterol and Alzheimer’s disease.
Fortunately, there are nutrients that can offset this oxidative stress — you know them as antioxidants. Antioxidants work to counteract the damage caused by free radicals.
But what does this have to do with probiotics? Well, it seems that one of the ways probiotics appear to benefit the digestive system is that they help increase the absorption of key nutrients, including antioxidants.
Armed with this knowledge, researchers from the University of Camerino in Italy set out to determine if probiotics could boost antioxidant protection in athletes.
They divided 24 amateur male athletes age 26 to 38 into two groups. The first group took a mixture of two probiotics strains (Lactobacillus rhamnosus and Lactobacillus paracasei) every day for four weeks. The second group didn’t receive any supplements.
Both groups followed the same intense workout program and schedule, and each group ate a diet created for them based on their personal metabolism, body composition and energy expenditure. All diets had the same amount of macro/micronutrients and had 100 percent of the recommended daily allowance for all nutrients.
Blood samples were collected from all participants at 8 a.m., on an empty stomach. Additionally, samples were taken for each participant immediately before and after probiotic consumption, and plasma levels of reactive oxidative metabolites (indicator of oxidative stress) and biological antioxidant potential (indicator of amount of antioxidants) was recorded. Fecal samples were also collected.
Researchers found that those participants taking the probiotics had significantly greater antioxidant levels in their blood than the control. This was not surprising.
Similarly, researchers found that intense exercise did, in fact, increase oxidative stress in both groups. However, the level of reactive oxidative metabolites in the probiotic group was significantly lower that that of the control group. In other words, the probiotics helped neutralize the oxidative damage.
What’s even more interesting is that, in the control group, the biological antioxidant potential decreased after exercise, while in the probiotics group, it increased. Or, to say it another way, antioxidant levels went down in the control group after intense exercise, but went up in those participants taking probiotics.
Researchers concluded that this data show that, while intense physical activity induces oxidative stress, probiotics can help to reduce oxidative stress. They go on to suggest that “athletes and all those exposed to oxidative stress may benefit from the ability of these probiotics to increase antioxidant levels and neutralize the effects of reactive oxygen species.”
Probiotics Also Reduce Upper Respiratory Infections
A similar study looked at probiotics’ ability to protect against upper respiratory infections in athletes training during the winter months.
In this double-blind, placebo-controlled study, researchers randomly divided 84 highly active people (30 women and 54 men) into two groups. The first group took a probiotic drink containing Lactobacillus casei every day for 16 weeks. The second group took a placebo. (Fifty-eight participants completed the full 16 weeks.) Both groups performed an average of 10 hours of moderate to vigorous exercise per week.
During the 16-week study period, participants were not permitted to take any additional supplements or probiotics, or consume any fermented dairy products (which, Ms. Curtis will remind us, contain probiotics). They were also asked to report any illnesses, including sore throats, congestion, runny nose, cough, sneezing, fever, aches and pains, headaches and sleep disturbances.
At the end of the study period, researchers found that those people taking the probiotics not only had 50 percent fewer upper respiratory episodes, but they also had 33 percent fewer days with upper respiratory infection symptoms. Moreover, even when symptoms were present, training was less affected in the probiotics group versus the control group.
Researchers concluded that “regular ingestion of [Lactobacillus casei] appears to be beneficial in reducing the frequency of [upper respiratory tract infections] in an athletic cohort.” Or, to put it in layman’s terms, probiotics help reduce the symptoms and frequency of respiratory infections in those who exercise regularly.
Get That Yogurt
Whether you are looking to improve digestion, fight free radical damage, or prevent upper respiratory infections, it looks like part of the solution lies with probiotics.
There are many ways to get these beneficial bugs. If you prefer food-based options, you can choose probiotic-rich, fermented foods such as yogurt, kimchee, pickles and sauerkraut.
On the supplement side, you can take probiotics pearls or a liquid form. Both can be found in most health food stores. Take as directed. And take often. Your body will thank you.
For more tips on how to improve your health starting today, read our Special Report: 7 Steps to a Healthier & Happier You — click here.
 Martarelli, D et al. Effect of a probiotics intake on oxidant and antioxidant parameters in plasma of athletes during intense exercise training. Curr Microbiol. 2011 Mar 12. [Epub ahead of print]
 Gleeson, M et al. Daily probiotic’s (Lactobacillus casei Shirota) reduction of infection incidence in athletes. Int J Sport Nutr Exercise Metab. 2011;21:55-64.