Probiotic Supplements Can Help Boost Immunity

No, It's Not Like War of the Worlds

In the H.G. Wells classic science fiction tale, War of the Worlds, the earth is saved from invading Martians by terrestrial microorganisms that overwhelm the aliens’ immune systems: the Martians get sick and die. While Wells recognized that creatures from another planet might lack immunity to earth’s pathogens, he and the scientists of his time had a simplistic view of human immunity. We humans who live on earth aren’t merely resistant to the local bugs. Instead, our immune cells team up with friendly bacteria called probiotics inside the human body to keep the deadly ones under control.

Medical research into how our bodies fight off diseases like the cold and flu has shown that most of our immune resistance takes place in the digestive tract. That is where billions of probiotics make their home, crowding out harmful infectious agents that can make us sick and stimulating our immune cells to do their jobs better – keeping them extra alert in a constant vigil against illness.

Chest Protector: Probiotics and Immunity

Recent studies on probiotic supplements demonstrate that these organisms can help the body resist respiratory infections like the flu and the common cold. A study in Germany, for instance, discovered that taking a supplement that contains probiotic bacteria with vitamins and minerals for three months during the winter and spring can alter your susceptibility to colds and flu. When the researchers compared the health of about 240 people taking the supplements with another 240 who went without, they found that the group taking probiotics suffered 13 percent fewer respiratory infections.

In addition to suffering fewer illnesses, when members of the group taking supplements did suffer from the flu their symptoms were reduced by 25 percent. Plus, they only suffered fevers for half the time the unsupplemented group did. Lab work performed by the scientists also showed that the people taking probiotics had more immune cells ready to take part in their immune defenses.

The scientists concluded: “the intake of a dietary probiotic supplement containing probiotic bacteria plus vitamins and minerals during a period of at least three months in winter/spring may reduce the incidence and the severity of symptoms in common cold infections…”

In another study, researchers in Finland found that giving probiotics for children reduced recurrent respiratory infections. On the other hand, many experts now believe that frequent ear infections in children may not be due to reinfections, but may take place because the harmful bacteria persists in the ear canal between illnesses. In those cases the bad bugs periodically overwhelm the immune cells and probiotics which normally remain in control. And if kids have to take antibiotics to control bacterial infections, parents are well advised to give them probiotics to help limit the diarrhea these medicines can cause. When researchers gave kids probiotic supplements between their doses of antibiotics, they reduced their diarrhea by about two thirds.

Exercise and Immunity

If you’re planning to do a lot of exercise in the next few months, probiotics can help you keep on your training program. While moderate exercise improves your resistance to disease, extremely intense exercise can weaken your immune system. Particularly susceptible: marathon runners who push their bodies to the limit so they can race more than 26 miles. For these athletes, probiotics may help keep them on the road and out of a sickbed. When researchers in Finland gave probiotics to runners training for a road race, they found the supplements significantly reduced their sick days and lessened their intestinal problems (a frequent complaint among long distance runners) by about 25 percent.

Cellular Protection

How do probiotic bacteria work their immunity magic? One method appears to be by triggering the release of proteins in the body called Toll-like receptors (TLRs). These proteins help maintain the health of epithelial cells and activate the body’s machinery that repairs injury. (Epithelial cells line the intestinal tract as well as the mouth and esophagus.) When probiotic bacteria are missing, as occurs when they are killed off by antibiotics, TLRs cannot perform their repair work. That lack of repair makes the body more vulnerable to invasion by pathogens which can breach the body’s protective membranes.

New Knowledge

When H.G. Wells was writing his novels, many medical researchers thought the only good microorganism was a dead one. But now we know that without friendly bacteria to help our immune systems stay strong, the flu bug and other infectious agents would do to us what they did to those fictitious Martians Wells wrote about.